UNIVERSITY  OF  CALIFORNIA  PUBLICATIONS 
COLLEGE  OF  AGRICULTURE 

AGRICULTURAL  EXPERIMENT  STATION 

BERKELEY,  CALIFORNIA 


CALIFORNIA  WHITE  WHEATS 


BY 
G.  W.  SHAW  and  A.  J.  GAUMNITZ 


BULLETIN  No.  212 

April,  1911 


8  A  C  R  A  M  K  N  T  0 

W.    W.    SHANNON  -  SUPERINTENDENT   STATE    PFJNTrNi. 

1911 


EXPERIMENT  STATION  STAFF. 


E.  J.  Wickson,  M.A.,  Director  and  Horticulturist. 

E.  W.  Hilgard,  Ph.D.,  LL.D.,  Chemist   (Emeritus). 

W.  A.   Setchell,  Ph.D.,  Botanist. 

Leroy  Anderson,  Ph.D.,  Dairy  Industry  and  Superintendent  University  Farm  Schools. 

M.  E.  Jaffa,  M.S.,  Nutrition  Expert,  in  charge  of  the  Poultry  Station. 

R.  H.  Loughridge,  Ph.D.,  Soil  Chemist  and  Physicist  (Emeritus). 

C.  W.  Woodworth,  M.S.,  Entomologist. 

Ralph  E.  Smith,  B.S.,  Plant  Pathologist  and  Superintendent  of  Southern  California 

Pathological  Laboratory  and  Experiment  Station. 
G.  W.   Shaw,  M.A.>   Ph.D.,   Experimental  Agronomist  and  Agricultural  Technologist, 

in  charge  of  Cereal  Stations. 

E.  W.  Major,  B.Agr.,  Animal  Industry,  Farm  Manager,  University  Farm,  Davis. 

F.  T.  Bioletti,  M.S.,  Viticulturist. 

B.  A.  Etcheverry,  B.S.,  Irrigation  Expert. 

George  E.  Colby,  M.S.,  Chemist  (Fruits,  Waters,  and  Insecticides),  in  charge  of 
Chemical  Laboratory. 

H.  J.  Quayle,  A.B.,  Assistant  Entomologist,  Plant  Disease  Laboratory,  Whittier. 

W.  T.  Clarke,  B.S.,  Assistant  Horticulturist  and  Superintendent  of  University  Exten- 
sion in  Agriculture. 

H.  M.  Hall,  Ph.D.,  Assistant  Botanist. 

C.  M.  Haring,  D.V.M.,  Assistant  Veterinarian  and  Bacteriologist. 
John  S.  Burd,  B.S.,  Chemist,  in  charge  of  Fertilizer  Control. 

E.  B.  Babcock,  B.S.,  Assistant  Agricultural  Education. 
W.  B.  Herms,  M.A.,  Assistant  Entomologist. 

J.  H.  Norton,  M.S.,  Assistant  Chemist,  in  charge  of  Citrus  Experiment  Station,  River- 
side. 
W.  T.  Horne,  B.S.,  Assistant  Plant  Pathologist. 

J.  E.  Coit,  Ph.D.,  Assistant  Pomologist,  Plant  Disease  Laboratory,  Whittier. 
C.  B.  Lipman,  Ph.D.,  Soil  Chemist  and  Bacteriologist. 
R.  E.  Mansell,  Assistant  in  Horticulture,  in  charge  of  Central  Station  grounds. 

A.  J.  Gaumnitz,  M.S.,  Assistant  in  Cereal  Investigations,  University  Farm,  Davis. 

E.  H.  Hagemann,  Assistant  in  Dairying,  Davis. 

B.  S.  Brown,  B.S.A.,  Assistant  in  Horticulture,  University  Farm,  Davis. 

F.  D.  Hawk,  B.S.A.,  Assistant  in  Animal  Industry. 

J.  I.  Thompson,  B.S.,  Assistant  in  Animal  Industry,  Davis. 

R.  M.  Roberts,  B.S.A.,  University  Farm  Manager,  University  Farm,  Davis. 

J.  C.  Bridwell,  B.S.,  Assistant  Entomologist. 

C.  H.  McCharles,  B.S.,  Assistant  in  Agricultural  Chemical  Laboratory. 
N.  D.  Ingham,  B.S.,  Assistant  in  Sylviculture,  Santa  Monica. 

E.  H.  Smith,  M.S.,  Assistant  Plant  Pathologist. 
T.  F.  Hunt,  B.S.,  Assistant  Plant  Pathologist. 

C.  O.  Smith,  M.S.,  Assistant  Plant  Pathologist,  Plant  Disease  Laboratory,  Whittier. 

F.  L.  Yeaw,  B.S.,  Assistant  Plant  Pathologist,  Vacaville. 
F.  E.  Johnson,  B.L.,  M.S.,  Assistant  in  Soil  Laboratory. 
Charles  Fuchs,  Curator  Entomological  Museum. 

P.  L.  Hibbard,  B.S.,  Assistant  Fertilizer  Control  Laboratory. 

L.  M.  Davis,  B.S.,  Assistant  in  Dairy  Husbandry,  University  Farm,  Davis. 

L.  Bonnet,  Assistant  in  Viticulture. 

S.  S.  Rogers,  B.S.,  Assistant  Plant  Pathologist,  Plant  Disease  Laboratory,   Whittier. 

B.  A.  Madson,  B.S.A.,  Assistant  in  Cereal  Laboratory. 

Walter  E.  Packard,  M.S.,  Field  Assistant  Imperial  Valley  Investigation,  El  Centre 

M.  E.  Stover,  B.S.,  Assistant  in  Agricultural  Chemical  Laboratory. 

P.  L.  McCreary,  B.S.,  Laboratory  Assistant  in  Fertilizer  Control. 

F.  C.  H.  Flossfeder,  Field  Assistant  in  Viticulture,  Davis. 

E.  E.  Thomas,  B.S.,  Assistant  Chemist,  Plant  Disease  Laboratory,  Whittier. 

Anna  Hamilton,  Assistant  in  Entomology. 

Mrs.   D.   L.   Bunnell,  Secretary  to  Director. 

W.  H.  Volck,  Field  Assistant  in  Entomology,  Watsonville. 

E.  L.  Morris,  B.S.,  Field  Assistant  in  Entomology,  San  Jose. 

J.  S.  Hunter,  Field  Assistant  in  Entomology,  San  Mateo. 

J.  C.  Roper,  Patron  University  Forestry  Station,  Chico. 

J.  T.  Bearss,  Foreman  Kearney  Park  Station,  Fresno. 

E.  C.  Miller,  Foreman  Forestry  Station,  Chico. 


CALIFORNIA  WHITE  WHEATS. 


KINDS  OF  WHEAT. 

Note. — The  major  part  of  this  bulletin  is  the  result  of  work  done  by  Mr.  A.  J. 
Gaumnitz  as  a  candidate  for  the  degree  of  M.S.  To  the  data  so  secured  has  been 
added  other  data  which  seemed  to  be  closely  related.  Credit  should  particularly  be 
given  to  Messrs.  B.  R.  Jacobs,  and  E.  J.  Lea,  for  portions  of  the  routine  chemical 
work,  and  to  Miss  Edith  Miller  for  the  microscopic  measurements. 


At  present  agriculturists  quite  generally  recognize  eight  species  of  the 
genus  Triticum,  as  follows :  Triticum  vulgare,  Triticum  compactum, 
Triticum  turgidum,  Triticum  durum,  Triticum  polonicum,  Triticum 
spelta,  Triticum  dicoccum,  and  Triticum  monococcum.  The  last  three 
species  named  are  of  little  value  in  this  country  directly,  and  become 
important  only  in  so  far  as  they  are  used  in  improving  the  commonly 
produced  varieties  by  methods  of  breeding.  Emmer  and  speltz  are 
grown  in  considerable  quantities  in  Russia,  Germany,  France,  Spain, 
Italy  and  Servia,  and  the  monococcum  (einkorn  or  engrain)  in  the  same 
countries,  but  to  a  lesser  extent.  Speltz  is  used  mainly  as  cattle  food. 
Emmer  and  monococcum  are  used  as  a  human  food  to  a  limited  extent. 

Though  the  botanic  characteristics  of  the  Poulard,  Polish  and  Durum 
types  are  quite  distinct  in  kernels  and  other  parts,  their  adaptation  and 
uses  are  very  similar.  They  are  quite  rank,  hardy  growers,  and  suited 
to  the  semi-arid  regions.  The  Durums  are  well  adapted  for  the  produc- 
tion of  macaroni. 

Durum  flour  when  blended  with  that  of  the  common  bread  wheats, 
produces  a  bread  which  compares  not  at  all  unfavorably  with  that  from 
ordinary  flours.  These  wheats  possibly  may  be  used  for  blending  to 
improve  the  common  wheats,  and  especially  California  white  wheats,  for 
they  are  relatively  high  in  gluten.  From  a  field  standpoint  they  are 
fairly  rust  resistant,  are  able  to  subsist  on  a  minimum  of  moisture  and 
at  the  same  time  withstand  quite  high  temperatures. 

The  common  bread  wheats  (Tr.  vulgare)  are  a  quite  variable  species 
and  are  the  most  extensively  grown  of  any  in  the  United  States.  They 
have  been  known  especially  for  their  bread-flour  producing  qualities, 
but  setting  aside  prejudice  it  is  questionable  whether  they  should  longer 
hold  that  title  to  the  exclusion  of  the  best  durum  varieties.  There  is  a 
considerable  difference  in  the  bread-making  qualities  of  the  different 
varieties  of  the  common  wheats,  and  when  the  durum  wheats  of  good 


316 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION. 


quality  are  ground  into  flour  and  baked,  in  comparison  with  the  bread 
wheats,  it  is  readily  seen  that  in  flour-jdelding  power,  color  and  lightness 
of  the  loaf  produced,  they  compare  very  favorably. 

The  hard  wheat  area  is  being  rapidly  extended  northward  into 
Alberta  and  adjacent  provinces.  This  class  of  wheat  is  what  the  Minne- 
apolis mills  grind  into  their  world-famed  flours.     Although  some  Kan- 


Bearded    type    of    common    wheat. 


Beardless    type    of 
common    wheat. 


A  Durum  wheat. 


Fig.  1. — Showing  typical  wheat  heads.     One  half  natural  size. 

sas  hard  wheat  is  also  used.  1h<y  depend  largely  upon  the  northern  hard 
wheat  for  the  quality  of  their  flour. 

In  contradistinction  to  the  hard  wheats,  we  ma}r  note  the  white  (or 
soft;  wheats  of  the  central  and  Pacific  coast  region.  These  wheats  are 
also  sM,l:''n  of  as  lnvjul  u  limits,  but  they  differ  as  widely  from  the  hard 
wjnter   wIm-;ik  grown    m   ili«-  north   central   states  as  do  the  durum 


Bulletin  212] 


CALIFORNIA    WHITE    WHEATS. 


317 


wheats,  so  that  for  technical  study  at  least  they  deserve  separation  and 
distinction. 

These  wheats,  as  indicated  by  the  name,  are  very  light  colored  as  com- 
pared with  eastern  wheats ;  and  further,  they  produce  a  very  white  flour. 
Some  of  these  flours  are  nearly  dead  white,  having  practically  no  color 
value  at  all.  Some  samples  have  so  little  yellow  that  the  lightest  tinted 
yellow  glass  of  the  Lovibond  tintometer  is  too  yellow  to  match  the  flour. 
The  Sonora  variety,  however,  yields  flour  that  has  even  more  of  the  yel- 
low color  than  the  average  eastern  flour. 


Fig.   2. — Showing  types   of  common   bread  wheats.      One  half  natural  size. 

The  wheats  most  widely  grown  in  California  are  Little  Club  (com- 
monly called  Salt  Lake  Club),  White  Australian,  Washington  Blue- 
stem,  Sonora,  and  Propo.*  There  are  a  few  other  varieties  scattered 
here  and  there  in  the  State,  but  the  above-named  varieties  are  the  only 
ones  which  can  be  said  to  have  a  wide  favor  with  farmers  in  the  large 
wheat-growing  areas  at  the  present  time.  Those  of  lesser  importance 
are  Golden  Gate  Club,  Defiance,  and  White  Chili. 

*Note. — This  wheat  is  sometimes  called  "Proper"   instead  of  Propo. 


318  UNIVERSITY   OF   CALIFORNIA — EXPERIMENT   STATION. 

At  this  date  it  is  impossible  to  obtain  any  very  accurate  information 
as  to  when  these  wheats  were  introduced  into  the  State,  but  doubtless 
most  of  them  came  from  Australia.  This  is  certainly  true  of  White 
Australian  and  probably  of  Sonora,  although  the  latter  may  have  come 
by  the  way  of  Mexico.  Of  the  former,  Mr.  G.  W.  McNear  writes  that  it 
was  imported  from  South  Australia  in  the  early  sixties.  It  is  even  now 
grown  there  under  the  name  of  White  Lammas. 

Sonora  is  also  grown  extensively  in  Australia  under  the  name  "  Velvet 
Pearl. ' '  Washington  Bluestem  is  a  strain  very  closely  related  to  White 
Australian,  and  is  probably  an  Australian  importation  corresponding  to 
the  variety  now  grown  there  under  the  name  of  Purple  Straw.  White 
Chili  was  imported  in  the  early  fifties,  and  if  not  the  same,  is  very 
closely  allied  to  Oregon  Big  Club.  Of  Propo,  Mr.  R.  M.  Shacklef  ord,  of 
Paso  Robles,  for  many  years  connected  with  the  milling  trade  of  this 
State,  is  authority  for  the  statement  that  this  variety  was  a  field  selec- 
tion from  a  sowing  made  from  a  shipment  of  wheat  from  Chili;  the 
selection  being  sufficient  in  quantity  to  seed  thirty  acres  of  land  in  the 
Panoche  Valley.  From  this  thirty  acres  there  was  produced  about  five 
hundred  sacks  of  wheat.     Mr.  Shacklef  ord  writes : 

"I  purchased  this  wheat  and  shipped  it  to  Mr.  A.  D.  Starr,  of  Marysville.  The 
name  given  to  this  wheat  at  the  time  I  purchased  it  was  'Snowflake,'  and  I  shipped  it 
to  him  under  that  name.  There  was  some  little  seed  left  in  the  country,  and  quite  an 
inquiry  arose  for  the  same  seed.  Mr.  Starr  returned  me  two  car  loads — one  in  the 
Salinas  Valley,  and  one  to  Hollister.  Pie  reported  to  me  the  proper  name  was  Propo. 
My  memory  is  that  was  the  name  that  was  given  to  it  at  the  time  I  purchased  it,  but 
old  settlers  tell  me  it  was  called  'Snowflake,'  and  that  until  it  was  returned  from  the 
north  it  was  not  known  as  'Propo.'  This  leads  me  to  believe  that  some  of  the  original 
seed  was  distributed  in  the  north  and  raised  much  as  it  was  in  San  Benito  County, 
and  that  it  received  the  name  Propo  or  Proper  from  the  party  who  there  grew  it. 
My  opinion  is  that  this  is  a  complete  history  of  the  introduction  of  Propo  wheat  into 
California." 

The  wheat  was  at  one  time  held  in  high  esteem  both  by  farmers  and 
millers.  The  latter  still  regard  it  highly  as  compared  with  the  other 
California  varieties,  but  growers  have  gradually  drifted  to  one  or 
another  of  those  mentioned  previously  as  giving  greater  returns  in  yield 
in  the  interior  valleys.  In  the  coast  sections,  however,  Propo  still  holds 
its  own  and  constitutes  the  bulk  of  the  wheat  there  produced. 


Bulletin  212] 


CALIFORNIA   WHITE    WHEATS. 


319 


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HELD  CHARACTERISTICS. 

WHITE  AUSTRALIAN. 

This  is  a  free-stooling,  prolific,  hardy,  late, 
mid-season  wheat.  It  is  quite  subject  to  rust 
attacks,  and  has  only  a  me- 
dium tenacity.  It  is  not  well 
adapted  to  the  coast  sections 
on  account  of  its  liability  to 
rust. 

CHARACTERISTICS    OF    GROWTH. 

Stools:  Fairly  abundant, 
spreading,  rather  creeping. 

Straw:  White,  strong,  sup- 
ple, rather  tall. 

Foliage :  Good  color,  abund- 
ant, drooping,  slightly  glau- 
cous. 

Heads:  Bald,  smooth,  long, 
regular,  somewhat  open,  rather  slender,  taper- 
ing. 

Spikelets:  Narrow,  two  to  three  grained,  not 
close. 

Grain:  Large,  long,  plump,  white,  soft, 
opaque,  starchy  interior.  The  grain  is  of  pleas- 
ing appearance  and  generally  of  good  bushel 
weight. 

A  typical  White  Australian  should  grade 
about  as  follows  (Fig.  4)  : 


Fig.  3. — White  Austra- 
lian  wheat. 


320 


UNIVERSITY    OF    CALIFORNIA — EXPERIMENT    STATION. 


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LITTLE    (SALT  LAKE)    CLUB. 

This  is  a  strong-growing,  medium- 
stooling,  hardy,  mid-season  wheat. 
It  is  very  subject  to  rust  attack. 
The  chaff  has  a  very  high  tenacity, 
this  being  one  of  the  particular 
points  in  its  favor  in  the  interior 
valleys  where  the  winds  are  strong. 
It  ripens  a  little  earlier  than  White 
Australian  and  is  somewhat  more 
prolific. 

CHARACTERISTICS    OF    GROWTH. 

Stools:  Few  and  erect,  strong- 
growing. 

Straw:  White,  strong  and  of  medium  height. 

Foliage:  Good  color,  fairly  abundant,  upright 
and  smooth. 

Heads:  Awnless,  smooth,  short,  flat,  compact; 
chaff  yellow  and  tenacity  high. 

Spikelets:  Wide,  2-5  grained,  close. 

Grain :  Medium  large,  short,  white,  irregular 
in  shape,  very  soft  and  starchy  interior.  The 
grain  has  a  flat  side  which  makes  it  apparently 
larger  than  is  really  the  case. 

A  good  type  of  the  Little  Club  should  have 
about  the  following  grade  (Fig.  6)  based  upon 
the  method  of  grading  by  sieves  as  set  forth  in 
Bulletin  181  of  this  station. 


Bulletin  212] 


CALIFORNIA    WHITE    WHEATS. 


321 


SONORA. 

This  is  a  light-stooling, 
rapid-growing,  early  wheat. 
It  is  much  subject  to  rust, 
hence  only  adapted  to  the 
interior  valleys.  Its  leaves 
are  narrow  and  thin,  and 
well  adapted  to  withstand 
considerable  drought.  For 
this  reason  it  has  been  the 
variety  which  has  held  its 
own   in   those   portions   of 

Fig.  7.— Sonora  wheat,   the    State    UlOSt    Subject    to 
One  half  size.  -.  v,  i  .-, 

drought,     namely    m     the 
southern  portion  of  the  San  Joaquin  Valle}. 


CHARACTERISTICS  OF  GROWTH. 

Stools :  Few  and  erect  with  medium  growth. 

Foliage :  Light  color,  not  abundant,  texture 
thin,  surface  rough. 

Heads:  Long,  medium  thick,  somewhat  flat, 
compact,  hairy  and  awnless. 

Spikelets :  Three-grained. 

Grain :  Short,  round,  plump,  white,  starchy 
interior.  It  is  of  unusually  pleasing  appearance 
and  of  good  bushel  weight. 

The  grading  of  a  good  sample  of  Sonora 
showed  as  follows  (Fig.  8)  : 


T'Cii 


$v 


W 


O   O 
c  "3, 


a 
-i; 

o  o 

8   Q  2 

'"'.     c   o 

£3  v 
bfl 

G 

£  ° 

p  Z 
tc  a 

~  o 

i  — 

A  w 

Ph  co 

^  w 

CD 

■S     .  *-■ 

§    rt  X 

-    G  o 
®  A 

Q       O 

5  a> 


3 
rt  bo 

c 


O  «S 


CO  £ 

5  ° 

O  CO 

> 

O  co 


O)   co 


"3    CO 


322 


UNIVERSITY   OF    CALIFORNIA — EXPERIMENT   STATION. 


Fig.  9. — Propo  wheat.     One  half  size. 


PROPO. 

This  is  a  fair-stooling,  medium  early, 
vigorous  growing,  bearded  variety. 
Its  yielding  capacity  is  unusually  good 
where  winds  are  not  too  severe.  The 
texture  of  the  leaf  is  rather  thin,  thus 
enabling  it  to  withstand  rather  severe 
drought. 

CHARACTERISTICS  OF  GROWTH. 

Stools:  Fairly  abundant,  slightly 
spreading. 

Straw:  Purplish  white,  medium 
strong,  good  height. 

Foliage:  Dark  green,  drooping,  only 
fairly  abundant,  slightly  rough. 

Heads :  Bearded,  smooth,  long,  open, 
medium  slender,  tapering. 

Spikelets :  Medium  wide,  open,  three 
grained. 


The  relative  percentage  distribution  of  these  several  sorts  of  wheat  in 
the  State  is  shown  in  the  following  table,  taking  the  points  named  as 
centers,  the  figures  given  being  the  results  of  estimates  of  a  large  num- 
ber of  buyers  in  the  several  regions. 

TABLE     L— SHOWING     COMPARATIVE     DISTRIBUTION     OF    VARIETIES     OF 

WHITE   WHEAT   IN   CALIFORNIA. 


Tributary  to 

(0 

I 

White 
Australian 

w 
n 
f 

3 

a 

o 
| 

1    3 

o 
o 

Visalia    

5 

0 
5 
0 

30 
50 
90 
20 
85 
0 
0 

30 
30 
70 
60 
50 
20 

0 
30 

5 
15 
50 

0 

10 
10 
40 
15 
10 
10 
20 
10 
0 
0 

0 
5 

10 
0 
5 

10 
0 

30 
0 
0 
0 

60 

50 
2 
0 
0 

10 
0 
0 
0 
0 

10 

5 
5 
3 
0 
0 
0 
0 
0 
0 

85 
40 

Fresno   

Madera    

Modesto  

Stockton  

Sacramento  

Woodland  

Marysville    

Chico   _ 

Salinas   

Paso  Robles 

Bulletin  212]  CALIFORNIA  WHITE  WHEATS.  323 

These  estimates  show  that  the  Little  Club  is  the  favorite  variety  in 
the  northern  portion  of  the  Sacramento  Valley,  that  it  declines  rapidly 
in  popularity  as  one  goes  southward  and  can  hardly  be  called  popular 
south  of  the  country  tributary  to  Stockton.  In  the  coast  section  it  is 
not  grown  at  all.  White  Australian  seems  to  have  a  more  widely  dis- 
tributed popularity  than  any  of  the  other  sorts.  It  has  its  widest  use 
in  the  middle  San  Joaquin  section  and  the  uplands  of  the  coast  region. 

Washington  Bluestem  has  come  into  wide  favor  during  the  last  few 
years  in  the  middle  San  Joaquin  section  and  its  use  is  extending  north- 
ward in  the  Sacramento  section.  This  wheat  has  all  the  characteristics 
of  the  White  Australian,  and  it  is  very  questionable  as  to  its  being  at 
all  different. 

White  Chili  can  be  said  to  be  popular  only  in  the  section  about  Marys- 
ville,  although  it  has  a  scattered  use  extending  even 
as  far  south  as  Fresno. 

Sonora  is  in  wide  use  only  in  the  southern  portion 
of  the  San  Joaquin  Valley,  where  its  marked  drought- 
resistant  qualities  have  doubtless  made  it  a  "survival 
of  the  fittest." 

Propo,  although  widely  grown  some  twenty-five 
years  ago  in  the  Sacramento  Valley,  has  been  super- 
seded entirely  by  other  wheat.  It  is  grown  to  a  con- 
siderable extent  now  only  in  the  coast  section,  espe- 
cially about  Paso  Kobles.  This  wheat  was,  and  still 
is,  held  in  high  esteem  by  the  milling  trade.  FlG' oL  Sf^teT"' 

IMPURITIES. 

Before  conducting  the  following  tests  the  samples  selected  were  sub- 
jected to  cleaning  for  the  removal  of  the  weed  seeds  present.  The  nature 
of  foreign  seeds  found  during  this  work  is  shown  in  the  following  table : 


324 


UNIVERSITY    OF    CALIFORNIA — EXPERIMENT    STATION. 


TABLE  II. — SHOWING  WEEDS  FOUND 


Number   of   Sample. 

44. 

62. 

67. 

73. 

80. 

1 

81. 

204. 

1.  Agrostemma  githago. 
Corn  cockle 

2.  Amsinckia  intermedia. 
Burweed,    fire-weed 

3 

50 

3.  Anthemis   cotula. 
Mayweed,  dog-fennel 

10 

4.  Avena  fatua. 
Wild  oats 

1 

5.  Avena  sativa. 

Cultivated  oats 

6.  Bromus  maximus. 
Broncho  grass 

59 

1 

22 

12          22 

7.   Centaurea. 

Star  thistle    (small  flower) 

8.   Convolvulus. 

Bindweed,  morning-glory 

9.   Gilia    (tiny  seeds) 

10.    Gnaphalium. 

Cudweed,    everlasting    (infinitesimal   seed) 

11.   Hemizonia. 
Tarweed 

9 
6 

12.   Hordeum   vulgare. 
Cultivated  barley 

33 

17 

256 

204 

2 

10 

13.   Leptocaulis    (parsley  family) 

14.   Lolium  perenne. 
Rve  grass 

1 

15.   Lolium  temulentum. 

Poison  darnel  ;  poison  rye  grass 

17.   Phalaris  paradoxa. 

Gnawed    canary    grass 

15 

3 

25 

48 

17 

18.  Medicago  denticulator. 

2 

19.   Raphanus  sativus. 
Wild  radish 

20.   Heliotropium  currassavicum. 
Wild  heliotrope 

20 

21.   Rumex  crispus. 
Curly  dock 

• 

22.   Vetch 

1 

Smut  wheat 

3 

107 
3.7 

20 

19 

9 

15 

301 

23 

12 

241 

13 

8 

75 

2.6 

20 

65 

2.2 

24.    Number  of  foreign  seeds 

40 

25     Percentage  of  impurities  (foreign  seeds) 

7.5 

The  table  is  of  interest  particularly  in  showing,  not  only  the  extreme 
more  aspecially  because  all  of  these  wheats  were  actually  being  used  by 
n ling  ih«'  case,  there  is  abundant  reason  for  the  extreme  weediness  of  the 
of  tlx*  combined  harvester  to  scatter  weed  seeds  in  the  fields. 


Bulletin  21: 


CALIFORNIA    WHITE    WHEATS. 


325 


IN  SEED  WHEAT  SAMPLES. 


206. 

208. 

211. 

229.   255. 

276. 

279. 

284.   289. 

296. 

300.   306. 

314. 

320.   325. 

208. 

1 

7 

2 

3 

72 
13 

66 
2 

36 
120 

8 

150 

1 

1 

8 

66 

1 

5 

13 

17 

3 

1 

1 
1 

6 

14 

1 

34 



2 

1 

2 

21 

50 

5 
6 

2 

80 

1 

2 

5 

14 

3 

17 

1 

4 

2 

1 

13 

34 

80 

30 

3 

121 

6 

17 

508 

56 
3 

6 

18 

11 

4 

122 

6 

10 

2 

1 

3 

1 

1 

125 

26.2 

...... 

257 
31.0 

1 
16 

2.7 

14 

39 

5.3 

2 

16 

2.0 

4 

109 

10.4 

6 

2 

.15 

11 
3.1 

100 
5.8 

517 
36.7 

69 
6.2 

20 

2.7 

70 
17.7 

21   222 
1.3   14.0 

323 
29.4 

weediness  of  the  field  on  which  most  of  these  wheats  were  grown,  but 
farmers  for  seeding  purposes  in  the  condition  here  represented.  This 
fields  in  the  Ayheat-srrowin^  areas  of  the  State,  aside  from  the  tendency 


326  UNIVERSITY    OF    CALIFORNIA — EXPERIMENT   STATION. 

PHYSICAL   CHARACTERISTICS   OF  WHEAT. 

The  physical  character  of  wheat  has  been  the  basis  of  much  study,  and 
certain  chemical  properties  have  been  shown  to  be  closely  associated  with 
well-defined  physical  characters.  The  milling  qualities  of  wheats  have 
also  been  found  to  be  more  or  less  closely  associated  with  certain  phys- 
ical features,  especially  size  of  grain,  hardness,  thickness  of  bran,  and 
bushel  weight. 

In  Bulletin  181  of  this  station  is  discussed  in  detail  the  matter  of  size 
of  kernel  of  a  large  number  of  samples  of  seed  wheat  collected  from 
farmers. 

The  relative  size  of  kernels  of  different  kinds  of  wheat  is  determined 
by  the  use  of  a  series  of  sieves,  by  weighing  a  definite  and  considerable 
number,  or,  what  amounts  to  the  same  thing,  counting  the  number  in  a 
certain  weight,  or  by  taking  the  weight  per  bushel.  No  one  method  can 
be  relied  upon  altogether,  because  of  the  variation  in  the  specific 
gravity ;  difference  in  maturity,  causing  the  grain  to  be  misshapen ;  and 
difference  in  normal  shape  of  the  kernels.  In  a  general  way,  these  dif- 
ferences are  equalized  and  eliminated,  by  taking  well-matured  grain  and 
depending  not  upon  individual  determination  but  upon  several  deter- 
minations and  averages  from  these. 

There  is  no  recognized  standard  to  represent  the  different  sizes  of 
grain,  but  after  considerable  study  of  the  range  of  variation  in  the 
grains  of  wheat,  the  following  meshes  have  been  adopted  as  suited  to 
the  conditions  of  this  study : 

Size.  12  3  4  5  6 

Mesh  diam.    3.25  mm.        3.00  mm.  2.75  mm.  2.50  mm.  2.25  mm.  2.00  mm. 


Fig.   11. — Showing  actual  size  of  grain  separated  by  each  sieve. 

The  common  method  of  the  grading  of  wheat  is  by  separation  of  the 
grains  according  to  size.  This  is  most  conveniently  done  by  means  of 
sieves.  The  grains  in  a  given  sample  vary  in  size.  If  the  sample  be 
passed  through  a  sieve  having  a  mesh  sufficiently  large  to  retain  only 
the  very  largest  grains,  and  then  successively  through  sieves  with 
smaller  and  smaller  meshes,  until  no  more  grains  will  pass  through,  the 
sample  will  have  been  graded,  that  is,  each  lot  or  pile  of  wheat  will  con- 
sist of  grains  of  a  definite  size. 


Bulletin  212] 


CALIFORNIA   WHITE    WHEATS. 


327 


The  character  of  the  mesh  has  much  to  do  with  a  proper  grading  by 
this  method.  The  shape  of  the  wheat-grain  is  such  that  a  slit  is  required 
for  the  openings  in  the  sieves  in  order  to  allow  the  passage  of  the  grain. 
An  examination  of  the  wheat-grains  will  show  that  the  two  transverse 
diameters  are  not  of  the  same  size,  and  this  must  be  regarded  as  hav- 
ing reference  to  the  shortest  diameter  in  each  case.  This  difference  in 
transverse  diameter  of  grain  is  easily  observed  in  Fig.  11. 

The  separations  were  in  each  case  made  upon  samples  consisting  of 
plump  grains.  The  grain  represents  the  crops  of  three  consecutive  years 
extending  from  1904  to  1906  inclusive. 


Fig.  12. 


-Showing  the  style  of  sieve  used  in  the  separation  of  the  different 
sizes  of  kernels. 


The  several  types  enumerated  above,  when  separated  by  means  of  the 
sieves  here  described,  gave  the  following  results  : 

TABLE  III.— SHOWING  MEAN  RELATIVE   SIZE   OF  GRAINS   OF  COMMON 

CALIFORNIA    WHEAT. 


No.  of 
sample. 

Size  1. 
3.25  mm. 

Size  2. 
3.00  mm. 

Size  3. 
2.75  mm. 

Size  4. 
2.50  mm. 

Size  5. 
2.25  mm. 

Size  6. 
2.00  mm. 

White  Australian  

Bluestem  

43 
32 
55 
11 

7 

11.62 

12.84 

14.52 

1.84 

8.56 

10.51 
11.63 

7.47 
2.53 
9.05 

24.71 
25.32 
17.13 
14.08 
17.68 

44.69 
40.56 
47.88 
57.10 
53.60 

7.01 

7.17 

10.25 

20.80 

9.96 

1.64 

2.40 

Little  Club  

2.72 

Sonora    

3.69 

Propo    _  

1.19 

The  above  table  of  grading  shows  certain  characteristics  of  the  grain 
which  will  also  be  observed  upon  studying  the  appearance  of  the  grains 
from  the  different  varieties  as  shown  in  the  illustrations.  In  the  first 
place  the  similarity  of  the  grading  of  White  Australian  and  Bluestem 
will  be  noted,  which  is  in  line  with  the  statement  made  in  an  earlier 
paragraph,  that  these  two  varieties  were  very  closely  related,  if  they  are 
not  even  the  same  variety  passing  under  different  names.  White  Aus- 
tralian carries  46.8  per  cent,  of  its  grains  in  the  first  three  sizes  while 


328  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION. 

49.7  of  the  grains  of  the  Bluestem  are  carried  in  the  same  sizes,  and 
further  it  will  be  noted  that  the  distribution  in  the  three  sizes  is  also 
essentially  the  same.  The  Little  Club  variety  is  distinctly  different 
from  these  types  and  also  from  those  following,  the  grading  giving  one 
the  idea  that  it  is  a  small  grain,  whereas  the  appearance  to  the  eye  gives 
one  the  impression  of  a  relatively  large  grain.  This  is  doubtless  due  to 
the  peculiar  shape  of  the  Club  grain.  It  has  one  flat  side  which  makes 
its  transverse  diameter  really  smaller  than  is  apparent.  Both  the  Propo 
and  the  Sonora  appear  from  the  grading  to  be  small  grains.  This  is 
actually  true  of  the  Sonora,  but  of  the  Propo  this  is  only  true  of  its 
transverse  diameter,  the  grain  being  rather  longer  than  that  of  the 
White  Australian. 

A  circumstance  shown  by  this  table  is  the  larger  weights  in  per  cent, 
retained  on  the  3.25  mm.  than  on  the  3  mm.  sieve  in  the  first  three 
cases.  One  would  expect  to  find  the  relations  which  are  shown  by  the 
Sonora  and  Propo.  In  an  examination  of  individual  determinations  a 
considerable  difference  is  found  in  favor  of  the  3.25  mm.  sieve.  The 
largest  being  24.2  per  cent,  on  the  larger  sieve  to  11.8  per  cent,  on  the 
next  lower  size,  while  below  this  the  percentage  increases  to  the  max- 
imum on  the  2.5  mm.  sieve. 

RELATION  OF  SIZE  OF  KERNEL  TO  FLOUR  YIELD. 

This  matter  of  size  of  grain  has  an  important  bearing  upon  the  mill- 
ing value  of  a  wheat,  especially  as  between  samples  of  the  same  variety 
other  things  being  equal.  For  instance,  of  two  wheats  otherwise  of 
equal  value  for  milling,  the  one  whose  grains  are  the  larger  will  give  the 
larger  yield  of  flour.  Millers  pretty  generally  recognize  this  by  screen- 
ing out  the  smallest  grains.  This  may  also  be  shown  by  certain  results 
obtained  with  the  mill  at  this  laboratory.  Further,  we  might  expect 
this  a  priori,  because  there  is  bound  to  be  larger  percentage  of  bran 
upon  the  smaller  grains  of  the  same  variety. 

The  following  table  is  intended  to  show  this  fact.  Here  is  shown  the 
average  grading  of  a  number  of  samples  of  grain,  each  of  which  has 
been  milled  so  as  to  secure  the  total  yield  of  flour  after  the  same  style  of 
milling.  For  the  sake  of  this  comparison,  the  first  three  sizes  are 
grouped  together  and  the  last  three  sizes  together,  and  are  arranged  in 
order  of  relative  size  of  grains,  the  total  number  of  samples  used  (52) 
being  separated  into  four  groups  of  thirteen  samples  each  for  securing 
an  average : 

TABLE  IV.— SF  JO  WING  THE  RELATION  OF  SIZE  OF  GRAIN  TO  YIELD  OF 

FLOUR. 


Xo    of   Samples    Represented 

Sizes 
1,  2,  3. 

Sizes 
4.  5,  6. 

Total 
flour  yield. 

13                      

5.3 
15.9 
28.9 
60.7 

94.7 
84.1 
71.0 
39.3 

691 

13                             - 

69  7 

13 . 

70.7 

1 3                 

71.4 

Bulletin  212] 


CALIFORNIA    WHITE    WHEATS. 


329 


PHYSICAL  CHARACTERISTICS. 

Table  V  shows  certain  physical  characteristics  of  the  grains.  In  it  is 
shown  the  relative  size  of  the  kernels  as  measured  by  the  number  in  10 
grams,  the  average  weight  per  kernel,  the  bushel  weight,  the  hardness 
when  tested  under  uniform  conditions,  and  the  grade  as  determined  by 
sieves  as  described  heretofore. 

In  Table  VI  is  given  a  summary  of  four  types,  the  grouping  being  in 
accordance  with  the  number  of  grains  per  10  grams,  and  subdivided 
into  groups  having  a  range  of  50  kernels  each.  In  each  case  the  num- 
ber of  samples  falling  in  each  group  is  given.  This  is  significant  in 
establishing  the  relation  between  the  four  types,  as  to  the  relative  num- 
ber of  samples  from  each  type  falling  in  the  same  group,  which  allows 
comparisons  to  be  made  between  the  different  kinds  of  wheat  of  the 
same  size  grain. 

TABLE   V.— SHOWING  AVERAGE   WEIGHT  AND  HARDNESS   OF   CALIFORNIA 

WHITE  WHEATS. 

Blue  st  em. 


Xo.  of 
Laboratory  kernels 

number.  '      in  10 

!     grams. 


Average 
weight 

per 
kernel. 


Weight 

per 
bushel. 


Number  of  unbroken   grains  under  weight  of 


.75  lbs. 


1.00  lbs. 


1.25  lbs. 


1.50  lbs. 


1.75  lbs. 


Total 
number  of 
unbroken 

grains.* 


64 

606 

118 

17 

24 

25 

152 

9 

303 

121 

268 

472 

15a 

10a 

16___ 

15 

4 

14 

371 

299 

267 

206 

205 

300 ' 

5 

386 

272 

Average  ___ 


225 
231 
237 
242 
242 
243 
245 
257 
263 
267 
268 
271 
277 
277 
279 
280 
285 
287 
292 
298 
309 
313 
313 
314 
314 
334 
350 


.0444 
.0432 
.0421 
.0413 
.0413 
.0411 
.0408 
.0389 
.0380 
.0374 
.0373 
.0369 
.0361 
.0361 
.0358 
.0357 
.0350 
.0348 
.0342 
.0335 
.0323 
.0319 
.0319 
.0315 
.0315 
.0299 
.0285 

.0363 


62. 
61. 

62.75 

61. 

59.50 

61. 

00. 

61.12 

61. 

62. 

60.25  i 

59. 

00. 

58.50 

60.12 

61.25 

57. 

61. 

59.50 

59.50 

59.75 

60.50 

60.75 

56.25 

60.25 

58.75 

59.50 

60.125 


100 

99 

100 

100 

93 

99 

94 

100 

100 

100 

100 

100 

100 

87 

100 

100 

100 

100 

99 

94 

95 

95 

72 

99 

100 

99 

100 

97 


100 
98 

100 
72 
68 
54 
84 
83 

100 
95 
88 
99 
89 
71 
43 
54 
47 
87 
74 
91 
74 
77 
63 
91 
43 
77 
86 

78 


96 
94 
91 
48 
41 
32 
64 
48 
84 
81 
54 
79 
66 
56 
28 
17 
20 
31 
37 
65 
37 
54 
51 
68 
22 
43 
63 

54 


82 
94 
75 
17 
20 
8 

40 

0 

58 

53 

16 

60 

36 

30 

0 

0 

0 

0 

12 

24 

12 

0 

19 
18 
0 
12 
50 

36 


59 
60 
42 
0 
0 
0 
5 
0 

25 

13 

2 

15 
0 
3 
0 
0 
0 
0 
0 
11 
6 
0 
7 
0 
0 
0 
22 

20 


437 
445 
408 
237 
222 
193 
287 
231 
367 
342 
260 
353 
291 
247 
171 
171 
167 
218 
222 
285 
224 
226 
212 
276 
165 
231 
321 

267 


•Note. — The  figures  in  this  column  represent  the  sum  of  the  figures  in  the  preceding 
five  columns. 


2— b212 


330 


UNIVERSITY   OF    CALIFORNIA EXPERIMENT    STATION. 


TABLE    V     (CONTINUED).— SHOWING    AVERAGE    WEIGHT    AND 
HARDNESS  OF  CALIFORNIA  WHITE  WHEATS. 


RELATIVE 


Australian. 


Laboratory 
number. 


No.  of 
kernels 
in  10 
grams. 


Average 
weight 

per 
kernel. 


Weight 

per 
bushel. 


Number  of  unbroken  grains  under  weight  of 


.75  lbs. 


1.50  lbs. 


Total 

number  of 

unbroken 

grains. 


452 

26 

67 

73 

416 

127 

605 

129 

68 

66 

23 

62 

453 

311 

231 

304 

134 

288 

232 

69 

138 

184 

322 

28 

275 

22 

141 

326 

309 

312 

78 

77 

319 

310 

359 

Average ._. 


292 


216 

.0462 

237 

.0421 

240 

.0416 

249 

.0401 

255 

.0392 

256 

.0390 

256 

.0390 

259 

.0386 

260 

.0384 

261 

.0383 

264 

.0378 

267 

.0374 

268 

.0373 

268 

.0373 

272 

.0367 

274 

.0364 

280 

.0357 

281 

.0355 

288 

.0347 

293 

.0341 

298 

.0335 

298 

0.335 

299 

.0334 

300 

.0333 

302 

.0331 

306 

.0326 

316 

.0316 

326 

.0306 

330 

.0303 

330 

.0303 

337 

.0296 

342 

.0292 

369 

.0271 

375 

.0266 

443 

.0225 

.0341 


59.5 

60.5 

62.75 

63.12 

58.25 

61.75 

62. 

60.50 

62.25 

61.25 

62.25 

62.75 

60.50 

61. 

63. 

62.50 

62. 

62.50 

59.50 

60.25 

00. 

60.50 

60.50 

60.25 

59. 

60.50 

00. 

61. 

59.50 

58. 

52.50 

60. 

59.50 

57.50 

53. 

60.29 


100 
100 
100 
100 
100 
100 
100 
100 
100 
100 

61 
100 
100 
100 
100 
100 

95 
100 

95 
100 

92 

97 
100 
100 

98 
100 

95 

96 

95 
100 
100 
100 
100 
100 

99 

97 


99 
99 
98 

100 
98 
91 

100 
83 

100 

100 
39 
81 
97 
98 
90 
96 
54 
96 
86 
95 
50 
80 

100 
99 
79 
99 
50 
87 
92 
99 
92 
95 
84 
66 
45 

86 


84 
90 
88 
90 
88 
37 
100 
50 
90 
93 
11 
47 
85 
91 


23 
86 
77 
61 

23 
22 
93 
85 
45 
85 
26 
72 
80 
92 
42 
58 
43 
18 
29 

65 


35 

61 

54 

24 

50 

0 

53 

0 

16 

28 

0 

0 

47 
0 
43 
9 
0 
27 
3 

10 
0 
0 
0 

25 

6 

25 

0 

14 
19 
12 
0 
0 
0 
0 
4 

26 


395 
434 
401 
375 
419 
232 
443 
240 
362 
396 
111 
248 
410 
323 
381 
327 
172 
365 
289 
278 
165 
199 
324 
355 
241 
355 
171 
293 
349 
325 
240 
264 
227 
184 
195 

299 


Bulletin  212] 


CALIFORNIA   WHITE   WHEATS. 


331 


TABLE 


V    (CONTINUED).— SHOWING    AVERAGE    WEIGHT    AND    HARDNESS 
OP  CALIFORNIA  WHITE  WHEATS. 


Little  Club. 


Laboratory 
number. 


No.  of 
kernels 
in  10 
grams. 


Average 
weight 

per 
kernel. 


Weight 

per 
bushel. 


Number  of  unbroken  grains  under  weight  of 


.75  lbs. 


1.00  lbs.  1.25  lbs.   1.50  lbs.  1.75  lbs 


Total 
number  of 
unbroken 

grains. 


Average 


210 
226 
235 
236 
243 
243 
244 
247 
248 
252 
255 
263 
271 
274 
282 
285 
286 
289 
292 
306 
311 
314 
315 
316 
317 
317 
330 
330 
332 
334 
336 
337 
340 
342 
355 
356 
360 
363 
363 
363 
363 
366 
367 
373 
377 
377 
390 
390 
419 
537 

323 


.0476 
.0442 
.0425 
.0425 
.0411 
.0411 
.0409 
.0404 
.0404 


.0392 
.0380 


.0364 
.0354 
.0349 
.0349 


.0342 
.0326 
.0321 
.0315 
.0317 
.0316 
.0316 
.0316 
.0303 
.0303 
.0301 
.0299 
.0297 
.0296 
.0294 
.0292 
.0281 
.0279 
.0277 
.0275 
.0275 
.0275 
.0275 
.0273 
.0272 
.0268 
.0265 
.0265 
.0256 
.0256 
.0238 
.0186 


59.50 

59. 

61.50 

62.50 

62.12 

63. 

60. 

61. 

63. 

60. 

60.75 

62. 

62. 

60. 

60.25 

63. 

00. 

62. 

61.25 

60. 

60.75 

00. 

59. 

58.50 

58.50 

60.75 

59. 

62. 

60. 

58.25 

61. 

00. 

59. 

60.50 

60. 

60.25 

59. 

60.50 

60. 

58.50 

59.50 

60.50 

57.75 

59. 

63. 

59.50 

61.12 

59. 

59.25 

58.87 


.0325  :   60.33 


100 

100 

100 

100 

100 

100 

100 

98 

100 

100 

100 

100 

98 

100 

100 

100 

94 

100 

100 

99 

100 

95 

100 

47 

47 

99 

97 

100 

100 

98 

100 

98 

100 

100 

100 

99 

94 

99 

54 

23 

23 

100 

100 

99 

72 

78 

100 

96 

95 

100 

92" 


100 
97 

100 

100 
99 
99 

100 
94 

100 
99 

100 

100 
81 

100 
80 
95 
83 

100 
92 
66 

100 
76 
84 
21 
21 
76 
70 
92 
63 
92 
93 
68 
43 
92 
96 
85 
35 
88 
46 
0 
0 

97 
60 
79 
43 
66 
92 
82 
37 
77 

80 


100 
96 
99 
98 
99 
97 
100 
94 
98 
94 
100 
99 
55 
97 
45 
89 
52 
97 
67 
21 
97 
34 
36 
9 
9 
39 
12 
57 
39 
72 
58 
30 
31 
64 
64 
54 
27 
47 
14 
0 
0 

63 
29 
40 
24 
41 
58 
41 
18 
48 

60 


100 

91 

95 

96 

97 

95 

96 

91 

85 

90 

90 

91 

10 

87 

10 

86 

13 

96 

13 

0 

86 

6 

7 

0 

0 

0 

2 

20 

0 

71 

23 

2 

0 

29 

30 

25 

25 

17 

8 

0 

0 

23 

0 

8 

10 

20 

24 

13 

0 

25 

48 


100 
83 
94 
90 
82 
87 
86 
33 
53 
62 
70 
79 
0 

59 

0 

77 

0 

86 
0 
0 

44 
0 
0 
0 
0 
0 
0 
6 
0 
7 
7 
0 
0 
4 
3 
5 
0 
5 
0 
0 
0 
3 
0 
0 
3 
0 
8 
0 
0 
0 

47 


500 
467 
488 
484 
477 
478 
482 
410 
436 
445 
460 
469 
244 
443 
235 
447 
242 
479 
272 
186 
427 
211 
227 
77 
77 
214 
181 
275 
202 
340 
281 
198 
174 
289 
293 
268 
181 
246 
112 
23 
23 
286 
189 
226 
152 
205 
282 
232 
150 
250 

288 


332 


UNIVERSITY    OF    CALIFORNIA — EXPERIMENT    STATION. 


TABLE    V 


(CONTINUED).— SHOWING    AVERAGE    WEIGHT    AND    HARDNESS 
OF  CALIFORNIA  WHITE  WHEATS. 


Sonora. 


Laboratory 

number. 


No.  of  ,    Average  j  Weight 

kernels  j      weight  I  per 

in  10              per  ,  bushel, 
grams.         kernel. 


Number  of  unbroken  grains  under  weight  of 


.75  lbs. 


1.25  lbs.      1.50 


1.75  lbs. 


Total 
number  of 
unbroken 

Efains. 


167 

481 

245 

74 

76 

33 

63 

249 

140 

137 

257 

Average 


254 

.0393 

61.50 

98 

92 

272 

.0367 

66. 

100 

100 

276 

.0362 

64.75 

100 

100 

296 

.0337 

65. 

100 

97 

337 

.0296 

63. 

100 

100 

356 

.0280 

64.25 

100 

96 

359 

.0278 

64. 

100 

93 

371 

.0269 

64.75 

96 

91 

444 

.0225 

61. 

100 

70 

457 

.0218 

63.50 

97 

65 

518 

.0193 

60.25 

94 

68 

358 

.0292 

63.45 

98 

88 

71 
100 
93 
87 
94 
87 
75 
75 
29 
24 
42 


35 

7 

99 

80 

77. 

34 

55 

25 

66 

32 

73 

52 

26 

9 

75 

33 

4 

0 

0 

0 

17 

0 

52 

34 

303 
479 
404 
364 
392 
408 
303 
370 
203 
186 
221 

330 


Propo. 


Laboratory 

No.  of 
kernels 
in  10 
grams. 

Average 
weight 

per 
kernel. 

Weight 

per 
bushel. 

Numbe 

•   of   unbroken   grains 

under  weight  of 

Total 
number  of 
unbroken 

grains. 

number. 

.75  lbs. 

1.00  lbs. 

1.25  lbs. 

1.50  lbs. 

1.75  lbs. 

46 

236 

270 
322 

341 

292 

.0423 
.0370 
.0310 
.0293 

.0349 

61. 

60.25 
63.50 
62.75 

61.87 

100 
100 
100 
100 

100 

100 
76 
92- 
94 

90 

89 

55 
78 
52 

69 

53 
40 
34 
14 

35 

27  '          369 

45  _ 

17             288 

47 _ 

7 
0 

17 

311 

79 

Average  ___ 

260 
307 

Bulletin  212] 


CALIFORNIA    WHITE    WHEATS. 


333 


TABLE  VI.— SHOWING   PHYSICAL   CHARACTERISTICS   OF   WHEATS   BY 

GROUPS. 

Bluestem. 


Range    of   seeds 
per   10   grams. 


Number  of  kernels  unbroken  under  weight  of       Sieve  grading. 


200-250— 
251-300— 
301-350— 

Average 


7 

238 

13 

277 

7 

321 

27 

274 

61.2 
60.0 
59.4 

60.2 


82 

66 

48 

27 

318 

68.3 

78 

51 

22 

5 

256 

54.4 

73 

48 

16 

5 

236 

35.2 

78 

55 

29 

12 

270 

52.6 

31.7 
45.6 
64.8 

47.4 


Australian. 


200-250— 
251-300— 
301-350— 
351-400— 

Average 


4 

234 

61.5 

100 

99 

88 

71 

43 

401 

65.5 

19 

274 

61.3 

97 

86 

66 

36 

15 

300 

50.3 

9 

321 

58.8 

98 

88 

65 

28 

12 

291 

31.8 

3 

396 

56.6 

100 

65 

30 

6 

1 

202 

10.4 

35 

306 

59.5 

99 

85 

62 

35 

18 

299 

39.7 

34.5 
49.7 
68.2 
89.6 

60.3 


Little  Club. 


200-250— 
251-300.  __ 
301-350— 
351-400— 

Average 


9 

237 

61.3 

100 

99 

98 

94 

79 

470 

72.6 

10 

275 

61.3 

99 

93 

80 

59 

43 

374 

60.1 

15 

325 

59.8 

92 

72 

41 

15 

4 

224 

30.8 

14 

359 

59.8 

81 

72 

41 

14 

2 

210 

15.0 

48 

299 

60.5 

93 

84 

65 

46 

32 

319 

48.1 

27.4 
39.9 
69.0 
85.0 

51.9 


Sonora. 


200-250— 
251-300— 
301-350. __ 
351-400— 
401-450— 
451-500— 

Average 


275 

64.3 

100 

337 

63.0 

100 

362 

64.3 

99 

444 

61.0 

100 

457 

63.5 

97 

518 

60.3 

94 

323 

63.8 

100 

97 
100 
93 
70 
65 
68 

97 


94 

79 
29 
24 

42 

87 


389 
393 
360 
203 
186 
221 


35.7 

10.4 

12.9 

0.0 

1.6 

2.5 


380       19.6 


64.3 
89.6 
87.1 
100.O 
98.4 
97.5 

80.4 


Grand  Average. 


200-250 
251-300 
301-350 
351-400 


246 
314 
332 


18       399 


62.1 
61.4 
60.4 
59.1 


99.5 

94.2 

85.0 

70.0 

47 

395 

60.5  ! 

98.5 

89.2 

72.7 

45.7 

25 

306 

43.8 

96.2 

815 

58.2 

28.5 

2 

266 

27.7 

93.6 

69.0 

33.6 

8.0 

1 

205 

8.5 

39.5 

56.2 
72.3 
91.5 


The  discussion  of  the  results  appearing  in  the  tables  of  physical  char- 
acteristics will  be  based  upon  the  small  tables  of  averages  (Table  VI) 


334  UNIVERSITY   OP    CALIFORNIA — EXPERIMENT   STATION. 

in  order  to  eliminate  the  influence  of  a  number  of  apparently  extreme 
variations  which  do  not  seem  to  be  entirely  consistent.  In  the  case  of 
Sonora  wheat  the  groups  350-400,  400-450,  450-500  are  also  eliminated 
in  making  up  the  averages,  inasmuch  as  but  a  single  sample  appears  in 
each  of  these  groups,  and  the  previous  table  shows  such  a  range  between 
different  samples  that  it  is  thought  unsafe  to  base  any  statement  upon 
these  groups  carrying  but  a  single  sample. 

Relative  Size  of  Varieties. — In  this  table  the  relative  size  of  the  sev- 
eral varieties  is  shown  in  two  ways,  namely,  the  average  number  of 
grains  in  10  grams  and  the  sieve  gradings,  sizes  1,  2,  3,  being  the  larger- 
sized  grains.  Considering  the  varietal  averages  as  shown  in  the  table, 
it  will  be  seen  that  as  to  size  of  kernel  the  varieties  stand  in  the  follow- 
ing order  in  both  instances :  Bluestem,  Little  Club,  Australian,  Sonora. 
A  constant  relation  is  seen  to  exist  between  the  size  of  grain  as  shown  in 
sieve  grading,  and  the  weight  per  bushel. 

The  table  shows  in  every  instance  that  the  weight  per  bushel  increases 
as  the  number  of  grains  per  10  grams  decreases,  that  is,  as  the  size  of 
the  kernel  decreases,  the  weight  per  bushel  decreases,  provided  the  type 
of  grain  remains  the  same,  but  if  the  type  changes  and  the  size  of  grain 
remains  the  same  the  weight  per  bushel  may  vary  widely.  As,  for 
instance,  the  bushel  weight  of  Bluestem  and  Little  Club  in  the  251-300 
group,  with  an  average  number  of  kernels  per  10  grams  respectively  of 
277  and  275,  the  Bluestem  weighed  but  60  pounds  per  bushel,  while  the 
Little  Club  showed  61.3,  or  a  difference  of  over  2  per  cent.  It  would 
appear,  then,  that  in  the  use  of  this  factor  in  the  judging  of  grains  it 
should  be  applied  only  to  lots  of  the  same  variety. 

Hardness  of  Kernels. — It  is  generally  held  that  the  hardness  of  a 
grain  gives,  in  a  rough  way,  its  general  adaptability  for  milling  pur- 
poses, particularly  if  the  test  be  applied  within  the  variety.  This  test 
is  usually  given  in  the  purchase  of  grain  by  the  biting  of  several  kernels, 
but  it  is  very  doubtful  if  an  approximate  idea  of  the  relative  hardness 
of  kernels  of  the  same  variety  can  thus  be  established.  As  between 
durum  varieties  and  the  white  wheats  it  would,  of  course,  be  possible  to 
differentiate,  and  also  between  the  darker-colored  wheats  of  the  middle 
west  and  white  wheats  of  the  west,  but  as  between  one  lot  of  Australian 
and  another  the  matter  is  very  doubtful.  Further,  it  has  certainly  not 
been  demonstrated  that  this  is  a  factor  of  importance.  Nevertheless,  an 
attempt  was  made  to  make  a  comparison  of  these  common  California 
sorts,  in  the  matter  of  hardness,  by  some  method  approximating  as 
nearly  as  possible  the  biting  method,  by  means  of  mechanical  means  of 
such  a  nature  as  to  measure  the  weight  used  in  each  case  to  break  the 
grain,  and  in  this  manner  establish  a  means  of  comparison  in  this 
respect. 


Bulletin  212] 


CALIFORNIA   WHITE   WHEATS. 


335 


The  apparatus  employed  consisted  of  a  pair  of  ordinary  pincers,  as 
shown  in  the  illustration,  mounted  upon  a  suitable  standard,  with  a 
weight  attached  to  the  upper  arm  by  means  of  a  wire.  A  number  of 
more  complicated  arrangements  were  tried,  but  none  seemed  to  give 
more  uniform  results  than  this  simple  contrivance.  The  tests  were 
made  with  five  different  weights — 0.75,  1.00,  1.25,  1.50,  1.75  pounds, 
respectively.  One  hundred  grains  were  counted  out  for  each  weight, 
and  the  hardness  obtained  by  opening  the  jaws  of  the  pincers  just 
wide  enough  to  insert  the  grain  between  them,  and  then  allowing  the 
weight  to  settle  gently.  The  grains  remaining  unbroken  by  each  weight 
were  set  aside  and  counted.  The  work  was  done  under  as  nearly  uni- 
form conditions  as  possible.  The  authors  are  inclined  to  doubt  the  fact 
that  the  hardness  of  the  grain  bears  any  very  definite  relation  to  the 
milling  value.  If  such  were  the  case,  one  would  expect  to  find  the  varie- 
ties under  such  a  test  as  this  arranging  themselves  in  nearly  the  same 


Fig.  13. — Showing  apparatus  used  in  testing  hardness  of  kernels. 

order  as  the  results  obtained  on  the  mill,  and  this  can  not  be  said  to 
have  been  the  case  in  the  case  of  individual  samples,  although  it  must 
be  admitted  that  the  general  trend  of  results  points  in  that  direction. 

The  facts  which  are  evident  from  this  trial  are  as  follows ;  within  the 
varieties  individually  the  larger  the  grain  the  harder,  which  it  will  be 
noted  is  in  the  same  direction  as  the  flour  yield.  This  appears  to  be 
true  in  each  one  of  the  varieties  tested,  without  exception.  Again,  the 
greater  the  weight  per  bushel  within  the  variety  the  harder  the  kernel. 
This,  of  course,  means  that  the  more  dense  the  kernel  the  greater  is  its 
weight  per  bushel,  other  things  being  equal.  Thus,  between  two  lots  of 
wheat  of  the  same  kind  of  different-sized  kernels  one  would  expect  to 
find  the  larger-sized  kernels  harder,  and  it  is  quite  evident  that  the 
larger-sized  kernels  will  also  give  a  greater  flour  yield.  The  quality  of 
the  flour,  however,  is  quite  apart  from  this  general  statement. 

As  between  the  varieties  it  is  to  be  noted  that  the  following  order  is 
shown ;  Sonora,  Little  Club,  Australian,  and  Bluestem.  This  is  quite  a 
different  order  than  would  probably  be  assigned  to  these  grains  by  a 


336  UNIVERSITY   OF    CALIFORNIA EXPERIMENT    STATION. 

miller,  who  would  probably  place  them  in  the  following  order  from  a 
milling  standpoint,  Australian,  Bluestem,  Sonora,  Little  Club.  There 
is  little  question  but  what  the  above-named  figures  represent  the  relative 
hardness  of  the  varieties  when  expressed  in  actual  weights,  which  would 
make  it  appear  that  the  action  under  the  rolls  involves  other  factors 
besides  the  hardness,  for  it  is  the  action  under  the  rolls,  which  the  miller 
has  learned  from  long  experience,  which  is  likely  to  govern  him  very 
much  wmen  he  attempts  to  judge  of  hardness  by  biting  the  grain ;  and 
the  difference  between  the  white  wheats  is  so  slight,  that  he  is  uncon- 
sciously influenced  almost  altogether  by  the  results  of  his  experience 
with  the  grains  under  the  rolls,  rather  than  by  the  real  hardness  of  the 
kernel. 

Indeed,  one  would  expect  the  Sonora  grains  to  be  the  harder  from 
their  general  appearance,  and  from  their  usually  higher  bushel  weight. 
The  grains  are  small  and  dense,  have  a  thin,  smooth,  glossy  bran  and 
more  than  make  up  in  weight  for  what  they  lack  in  size,  and  this  greater 
density  is  shown  in  their  relative  hardness  as  compared  with  the  other 
varieties  tested. 

THICKNESS  OF  BRAN. 

The  thickness  of  the  bran  is  recognized  by  millers  as  having  more  or 
less  to  do  with  the  milling  characteristics  of  wheats,  and  some  prelim- 
inary work  was  undertaken  in  connection  with  these  investigations 
towards  a  measurement  of  the  thickness  of  the  bran  of  the  varieties  of 
wheat  under  trial. 

For  this  preliminary  work  ten  typical  heads  of  "White  Australian 
were  selected  for  examination. 

Answers  to  two  questions  were  sought :  First,  is  the  thickness  of  the 
bran  fairly  uniform  in  the  same  kernel ;  second,  is  the  thickness  of  the 
bran  of  kernels  from  different  parts  of  the  same  head  fairly  uniform  ? 

Preparation  of  the  Grain. — To  toughen  the  grain  for  section  cutting 
it  was  first  soaked  in  water,  and  then  allowed  to  dry  thoroughly  on  the 
slide.  The  section  was  cleared  with  clove  oil,  and  to  free  the  prepara- 
tion from  air  bubbles  the  dry  section  was  treated  with  alcohol  just 
before  treatment  with  clove  oil. 

The  drawing  was  done  by  the  aid  of  a  camera  lucida  attachment  to 
the  microscope.  An  outline  of  the  outer  and  inner  edges  of  the  bran 
was  drawn,  and  the  average  width  determined  by  measurement.  Meas- 
urements were  made  at  three  points  upon  each  grain  on  cross  sections 
made  at  the  ovary  end  of  the  kernel,  at  the  center  and  at  the  beard  end 
of  the  kernel,  about  20  measurements  being  made  upon  the  bran  of  each 
cross  section. 

In  all  60  kernels  were  thus  examined,.  2  grains  being  taken  from  the 
top,  2  from  the  bottom  and  2  from  the  center  of  each  of  the  10  heads. 


Bulletin  212] 


CALIFORNIA   WHITE    WHEATS. 


337 


Of  these  three  fourths  of  the  thickest  sections  were  at  the  beard  end  of 
the  kernels,  but  not  much  variation  appeared  from  the  center  to  the 
ovary  end. 

TABLE   VII— SHOWING   MEASUREMENTS    OF   THICKNESS    OF   BRAN    IN    TEN 
HEADS   OF  WHITE  AUSTRALIAN  WHEAT. 


A. 


Ovary 
end. 


Beard 
end. 


end. 


Middle. 


Beard 

end. 


Third  kernel  from  top  of  head— 

1 

2 

Middle  of  head — 

1 

2 

Third  kernel  from  bottom  of  head 

1 

2 

Third  kernel  from  top  of  head— 

1 

2 

Middle  of  head— 

1 

2 

Third  kernel  from  bottom  of  head 

1 

2 

r< 
1 
2 
Id 
1 
2 
r< 
1 
2 

Third  kernel  from  top  of  head— 

1 

2 

Middle  of  head— 

1 

2 

Third  kernel  from  bottom  of  head 

1 

2 


2.8 

3.3 

3.4 

2.5 

2.4 

3.4 

3.1 

3.6 

2.9 

2.4 

3.7 

2.7 

3.6 

2.7 

3.6 

3.8 

3.1 

3.2 

3.3 

2.8 

3.1 

3.4 

3.5 

2.9 

3.1 

3.1 

3.4 

3.8 

3.0 

2.8 

c. 


D. 


3.0 
3.5 

2.7 
2.6 

3.0 
3.1 


2.9 

3.1  I 

3.1 
2.9 

3.9 

3.0 


3.6 

2.8 

3.4 
3.8 

2.9 


2.4 

2.8 

2.7 

2.6 

2.7 

3.1 

3.3 

2.9 

2.7 

3.3 

2.8 

2.7 

3.4 
3.3 

4.0 

3.0 

3.5 

3.5 


2.8 
2.9 

3.5 

2.7 

3.5 
2.9 


E. 


Third  kernel  from  top  of  head— 
1 

2.6 
2.6 

2.6 

2.4 

2.5 
2.7 

2.8 
3.1 

3.0 
2.9 

3.3 
3.2 

2.7 
2.7 

3.6 
3.1 

3.5 
3.5 

2.9 

2.7 

3.2 
3.0 

2.9 

2.5 

2.8 
2.6 

3.3 
3.1 

3.7 
2.9 

3.7 

2                       

3.3 

Middle  of  head — 

1    _ 

3.3 

2        _  _    ___    

3.8 

Third  kernel  from  bottom  of  head— 
1 ___           

3.3 

2 

3.1 

H. 


3.0 
2.9 

3.3 


3.0 
3.1 


2.7 
2.5 

3.8 
3.2 

3.0 
3.0 


3.2 
3.7 

4.0 
3.7 

3.5 

3.8 


3.3 

2.8 

3.3 

2.6 

2.4 

3.2 

3.5 

3.4 

3.9 

3.0 

3.0 

3.5 

2.9 

3.3 

3.6 

3.7 

3.4 

3.3 

338 


UNIVERSITY   OF    CALIFORNIA — EXPERIMENT    STATION. 
TABLE  VII — Continued. 


I. 

J. 

Ovary 
end. 

Middle. 

Beard 
end. 

Ovary 
end. 

Middle. 

Beard 
end. 

Third  kernel  from  top  of  head— 
1 

2.5 

2.8 

2.9 
2.9 

2.7 
2.3 

3.2 

2.6 

2.8 
2.9 

3.3 
3.0 

3.5 
3.0 

3.9 
3.6 

2.9 
3.6 

1 

2.6 

2.8 

3.0 
3.2 

2.9 
2.9 

3.2 
2.8 

2.8 
3.1 

3.0 
3.0 

3.9 

2                                  

3.1 

Middle  of  head — 

1 

3.9 

2               

3.5 

Third  kernel  from  bottom  of  head— 
1 

3.5 

2 

3.2 

Collecting  these  results  so  as  to  show  the  variation  a  little  more  closely 
by  averaging  the  measurements  for  each  of  the  two  grains  from  the 
several  heads  we  have  as  follows : 


Third  Kernels  from  Top  of  Head 

Head. 

A 

B 

O 

D 

E 

F 

G 

H 

I 

J 

Average. 

Kernel  No.  1 

Kernel  No.  2 

Average    

3.16 
3.33 

3.14 

2.76 

2.86 

2.81 

3.16 
3.13 

3.09 

2.66 
2.73 

2.69 

2.70 
2.80 

2.75 

3.13 

2.86 

2.99 

2.96 
3.03 

2.99 

3.13 
2.73 

2.92 

3.06 

2.80 

2.93 

3.23 
2.90 

3.06 

2.995 
2.917 

2.956 

Middle  Kernels. 


Kernel  No.  1. 
Kernel  No.  2. 


Average 


3.33 
3.33 

3.30 
3.03 

3.06 
3.10 

3.10 
2.96 

3.06 
2.80 

3.26 
3.30 

3.90 
3.40 

3.60 
3.16 

3.20 
3.13 

3.23 
3.26 

3.33 

3.16 

3.08 

3.03 

2.93 

3.18 

3.55 

3.38 

3.16 

3.24 

3.284 
3.147 

3.215 


Third  Kernel  from  Bottom  of  Head. 


Kernel  No.  1. 
Kernel  No.  2. 

Average    


3.33 
3.43 

3.10 
3.23 

3.26 
3.23 

3.16 

2.80 

3.10 
3.13 

3.30 
2.83 

3.16 
3.30 

3.26 
3.46 

2.96 
2.96 

3.13 
3.03 

3.38 

3.16 

3.19 

2.32 

3.11 

3.06 

3.23 

3.36 

2.96 

3.08 

3.176 
3.140 

3.158 


These  figures  indicate  that  there  is  considerable  variation  in  the  thick- 
ness of  the  bran  on  different  parts  of  the  same  kernel,  and  that  the  bran 
from  kernels  on  the  center  of  the  head  is  thicker  than  in  kernels  from 
either  end. 


Bulletin  212]        CALIFORNIA  WHITE  WHEATS.  339 


Chart  showing  Thickness  of  Bran   of  White  Australian  Wheat 
Third  Kernel  from  Top  of  SpiKe 


Middle  Kernel 


Third  Kernel  from  Bottom  of  Spike. 


340 


UNIVERSITY    OF    CALIFORNIA — EXPERIMENT    STATION. 


Similar  measurements  were  made  in  the  case  of  Little  Club,  which 
gave  the  following  average  results : 


Ovary 
end. 

Center. 

Beard 
end. 

Average. 

Top  of  head 

Middle  of  head 

3.0  - 

3.1  - 
3.1  - 

3.06 

3.3  - 
3.3  + 

3.3  - 

3.30 

3.4  + 
3.6 

3.5  + 

3.50 

3.23 
3.33 

Bottom   of   head _    _    

3.30 

Mean _                            _    

3.29 

Here  again  the  same  facts  appear  as  in  the  case  of  "White  Australian, 
namely,  as  to  the  individual  kernel,  the  bran  was  the  thickest  at  the 
brush  end ;  and  with  reference  to  the  location  on  the  spike,  the  thickest 
bran  was  found  on  the  kernels  from  the  middle  of  the  head. 


THE  CHEMICAL  COMPOSITION  OF  WHEATS. 


The  question  of  the  relation  of  the  chemical  composition  of  wheats  to 
their  baking  or  milling  value  has  been  one  which  has  attracted  the  atten- 
tion of  chemists  both  in  this  country  and  abroad  for  many  years,  but 
up  to  the  present  time  its  complete  solution  has  baffled  their  skill. 
While  this  is  true,  some  advance  has  been  made  and  certain  factors 
which  undoubtedly  have  a  bearing  upon  their  quality  as  related  to  bak- 
ing have  been  determined;  but,  nevertheless,  it  must  be  admitted  that 
we  are  still  far  from  a  very  intimate  understanding  of  the  true  relation 
of  these  factors.  It  is  probably  unnecessary  to  devote  any  space  to  a 
discussion  of  the  real  practical  value  which  chemical  data  would  have, 
provided  they  could  be  correlated  on  a  correct  basis  with  the  baking 
value  of  wheat  or  flour. 

It  is  not  likely  that  they  would  have  a  very  close  relation  to  the  mill- 
ing value  except  as  such  value  is  related  to  the  baking  value,  because 
the  milling  value  per  se  may  be  quite  independent  of  the  baking  value 
of  the  flour.  The  milling  qualities  of  a  wheat  are  almost  entirely 
dependent  upon  the  physical  characteristics  of  the  grain,  while  the  bak- 
ing characteristics  of  the  flour  are  evidently  quite  closely  related  to  cer- 
tain chemical  factors.  The  miller  is  primarily  interested  in  a  large 
yield  of  flour  of  good  appearance,  while  the  prime  question  with  the 
baker  is  that  the  flour  shall  have  a  sufficient  "strength"  for  his  special 
purpose.  A  wheat  may  have  excellent  milling  qualities  and  still  yield 
a  flour  quite  unsatisfactory  to  the  consumer,  and  vice  versa.  The 
dormer  condition  is  far  loo  often  the  case  with  the  California  wheats, 


Bulletin  212]  California  white  wheats.  341 

and  this  was  the  basal  reason  for  the  inauguration  of  the  cereal  investi- 
gation in  which  this  Station  is  now  engaged. 

It  is  quite  obvious,  then,  that  the  term  "strength"  and  "quality"  are 
not  interchangeable,  but  have  quite  distinct  meanings.  The  former 
refers  to  something  which  is  rather  definite  in  nature,  notwithstanding 
we  have  not  as  yet  fully  ascertained  what  are  the  factors  which  deter- 
mine the  so-called  ' '  strength. ' '  The  ' '  quality  "  of  a  flour  depends  much 
upon  the  purpose  for  which  it  is  intended.  It  may  be  very  high  for 
pastry,  but  very  poor  for  bread.  A  flour  which  has  very  high 
1 '  strength ' '  is  usually  of  lower  ' '  quality ' '  for  pastry  purposes  than  one 
of  much  lower  strength.  On  the  other  hand,  high  "strength"  is 
extremely  desirable,  and  well-nigh  essential,  for  the  making  of  good 
light  bread,  or  macaroni. 

The  general  composition  of  wheats  does  not  differ  materially  from 
that  of  other  organic  bodies,  in  that  it  is  made  up  of  several  different 
groups  of  constituents,  viz.,  moisture,  ash,  crude  protein,  fats,  and 
carbohydrates.  These  are  not  distinct  and  separate  compounds,  but 
are  groups  of  bodies  having  similar  properties  or  food  value  within  each 
group.  Thus,  for  instance,  the  term  carbohydrates  is  a  general  term, 
embracing  a  large  number  of  substances,  as  sugars,  starches,  certain 
gums,  etc.,  while  protein  is  the  name  of  a  general  class  of  bodies  con- 
taining nitrogen  as  an  essential  ingredient,  examples  of  which  are  albu- 
min or  the  white  of  eggs,  the  lean  meat  of  animal  bodies,  the  gluten  of 
flour,  etc.    The  composition  may  be  graphically  represented  as  follows : 


r 

1  Gliadin. 
j  Glutenin. 

Nitrogen- 

.   Proteids 

\ 

|        Non- 

C    Water. 

ous 

i  Edestin. 

I 

(.  Proteids 

J  Leucosin. 

'  Organic 

- 

(  Amides. 

STHEAT. 

{ 

f  Fats  or  Ether  Ext. 

1     Dry 

Non- 

| 

[_    Matter. 

Nitrogen- 

i 

C  Nitrogen- 

cms 

|    Carbo- 

^  hydrates 

|    free  Ext. 
J 

Mineral— 

-Ash. 

j    Crude 

[  Fiber. 

In  all  cases  water  is  present.  In  many  instances  this  is  very  evident, 
as  in  grass,  beets,  turnips,  etc.,  while  in  other  material  it  is  not  so  evi- 
dent, yet  when  they  seem  perfectly  dry  under  ordinary  conditions, 
there  is  from  5  to  10  per  cent,  moisture  present.  This  water  has  no 
more  food  value  than  that  taken  from  wells  or  streams.  It  is,  however. 
a  necessary  constituent  of  organic  material.  Moisture  is  determined  in 
the  laboratory  by  heating  the  material  for  a  long  time  at  the  tempera- 
ture of  boiling  water. 

After  the  moisture  has  been  driven  off  there  is  left  the  dry  matter, 
which  is  partly  organic  and  partly  mineral  in  its  composition. 


342  UNIVERSITY   OF   CALIFORNIA — EXPERIMENT   STATION. 

The  mineral  matter  of  plants  is  expressed  by  the  term  ash.  It  is  the 
residue  left  after  burning  to  perfect  whiteness. 

The  organic  matter  embraces  two  well-marked  classes,  viz.,  those  con- 
taining the  element  nitrogen,  nitrogenous ;  and  those  which  lack  nitro- 
gen, non-nitrogenous.  Of  all  the  material  composing  a  foodstuff,  the 
nitrogenous  matter  is  the  most  important.  It  embraces  both  proteids 
and  non-proteids,  which,  however,  are  not  usually  separated,  but  classed 
together  as  protein. 

The  nitrogenous  compounds  of  wheat  consist  principally  of  proteids 
of  which  five  have  been  recognized  and  described  by  Osborne  and  Voor- 
hees  as  follows : 

1.  A  globulin,  soluble  in  saline  solutions,  and  not  coagulable  at  a  tem- 
perature below  100°  C.     This  constitutes  0.6-0.7  per  cent,  of  the  grain. 

2.  An  albumin,  coagulable  at  52°  C.  It  differs  from  animal  albumin 
in  several  important  particulars.  It  constitutes  from  0.3-0.4  per  cent, 
of  the  kernel. 

3.  A  proteose,  which  is  extracted  from  the  wheat  by  dilute  saline  solu- 
tions after  removing  the  globulin  by  dialysis  and  the  albumin  by  coagu- 
lation.    It  constitutes  0.2-0.4  per  cent  of  the  kernel. 

4.  Gliadin,  a  proteid  body  soluble  in  dilute  alcohol,  and  forming 
nearly  one  half  of  the  total  proteid  matter  of  the  kernel. 

5.  Glutenin,  which  is  insoluble  in  water,  dilute  saline  solutions,  and 
dilute  alcohol,  and  which,  together  with  gliadin,  forms  nearly  the  entire 
proteid  content  of  the  wheat  kernel. 

Gluten. — Chemists  divide  the  above  indicated  proteids  into  two  gen- 
eral classes,  viz.,  gluten  and  non-gluten  proteids.  Gluten  is  a  mixture 
of  gliadin  and  glutenin.  It  is  the  amount  and  quality  of  gluten  which 
gives  to  flour  ability  to  rise  into  a  light  and  spongy  loaf  of  bread.  In 
the  process  of  bread  making,  the  carbonic  acid  gas  liberated  during  the 
fermentation  period  is  imprisoned  by  the  sticky,  elastic  gluten,  and  as 
the  gas  expands,  causes  the  bread  to  become  porous. 

Crude  gluten  can  be  obtained  either  from  a  wheat  meal  or  flour  by 
washing  out  the  starch  and  water-soluble  portions  from  a  dough  made 
by  kneading  the  meal  with  water.  In  this  condition  it  will  carry  about 
two  thirds  of  its  weight  of  water  and  certain  impurities  which  are  fairly 
constant  in  different  samples.  "A  good  gluten  has  a  light  yellow  color, 
is  tenacious  and  elastic,  while  poor  gluten  is  dark  in  color,  sticky  but 
not  elastic."* 

As  the  gluten  of  wheat  is  that  constituent  which  causes  the  flour  to  be 
strong,  wheats  to  be  of  high  baking  quality  should  carry  a  high  per- 
centage of  gluten.  This  high  percentage  of  itself,  however,  is  not  suffi- 
cient, since  it  is  found  that  glutens  differ  much  in  quality,  some  are 
tough  and  elastic  and  others  not.     Again  the  latter  generally  are  able 

*  Hunt's  Cereals  in  America,  page  41. 


Bulletin  212]  CALIFORNIA  WHITE  WHEATS.  343 

to  retain  a  very  much  smaller  amount  of  water,  resulting  in  a  corre- 
spondingly less  number  of  loaves  per  barrel  of  flour.  To  be  of  high 
quality  a  gluten  should  be  highly  elastic. 

It  has  been  claimed  by  some  writers  that  the  quality  of  a  gluten  is 
much  dependent  upon  the  proportion  of  the  gliadin  and  the  glutenin 
present.  M.  E.  Fleurent,  a  French  investigator,  states  that  the  most 
favorable  ratio  of  gliadin  to  glutenin  in  flour  is  75  to  25.  Snyder, 
formerly  of  the  Minnesota  Experiment  Station,  states  that  80  to  85  per 
cent  of  the  total  protein  should  be  gluten,  and  of  this  the  proportion  of 
gliadin  to  glutenin  should  be  60  to  65  per  cent. 

Later  work  of  Snyder,  however,  seems  to  cast  some  doubt  as  to  the 
value  of  this  matter  of  proportion  of  gliadin  to  glutenin,  for,  in  1905,  a 
year  later  than  the  former  statement,  he  writes :  ' '  As  our  work  on  this 
point  extends  over  a  number  of  years  it  appears  that  it  is  more  a  ques- 
tion of  total  gliadin  than  the  ratio  of  gliadin  to  glutenin."  The  results 
presented  in  the  later  pages  of  this  bulletin  seem  to  bear  out  this  latter 
statement  of  Snyder  and  to  cast  grave  doubt  upon  the  possibility  of 
correlating  the  gliadin-glutenin  ratio  closely  with  the  bread-making 
value  of  a  wheat  or  flour. 

Fats. — Nearly  all  foodstuffs  contain  more  or  less  fat.  Here,  again, 
the  term  is  not  used  in  as  definite  a  sense  as  in  ordinary  language,  but 
rather  refers  to  a  class  of  bodies  which  have  a  similar  composition,  and 
since  they  are  determined  by  extraction  with  ether,  many  chemists  pre- 
fer to  use  the  name  Ether  Extract.  It  really  denotes  more  than  fat  in 
the  case  of  green  foodstuffs,  as  the  coloring  matter  and  certain  gums  are 
extracted  at  the  same  time,  but  in  grain  the  extract  is  nearly  all  fats 
and  oils.  These  do  not  differ  in  any  essential  particular  from  the  ani- 
mal fats  and  oils,  which  all  belong  to  a  class  of  bodies  known  as  glycer- 
ides.  The  fat  of  wheat  is  not  a  very  important  element  in  determining 
its  value. 

The  Carbohydrates  are  usually  separated  into  Crude  Fiber,  and 
another  class  called  Nitrogen-free  Extract.  The  former  is  the  woody 
tissue  of  the  plant,  which  remains  after  successive  boilings  with  a  weak 
acid  and  a  weak  alkali.  It  is  found  principally  in  the  bran.  Carefully 
conducted  experiments  show  that  even  this  woody  fiber  has  a  nutritive 
value,  a  small  quantity  usually  being  digested.  Still  the  value  of  food- 
stuffs usually  varies  inversely  as  the  amount  of  crude  fiber  present. 
The  Nitrogen-free  Extract  is  composed  of  a  number  of  substances  as 
starch,  sugar,  dextrin,  and  gums,  grouped  together  because  similar  in 
composition. 

Starch  is  the  most  important  of  the  carbohydrates  of  wheat  and  con- 
stitutes from  64  to  70  per  cent,  of  the  kernel.  It  is,  of  course,  of  great 
importance  as  the  principal  foodstuff  in  bread.     Sugar  and  dextrin  are 


344  UNIVEESITY    OF    CALIFORNIA— EXPERIMENT    STATION. 

other  compounds  which  are  present  in  wheats  in  quite  small  quantities. 
In  sound  wheat  if  sugar  be  present  it  should  be  in  the  form  of  cane 
sugar.     Should,  however,  the  sugar  be  in  the  form  of  maltose  it  would 
undoubtedly  indicate  a  partial  hydrolysis  of  starch  and  would  be  object 
ionable.     The  same  may  be  said  with  regard  to  the  presence  of  dextrin. 

Incomplete  as  are  the  present  laboratory  methods,  they  still  furnish 
results  of  considerable  value  in  a  broad  classification  of  wheats  and 
flours,  even  if  failing  to  distinguish  between  two  samples  of  approx- 
imately the  same  ' '  strength. ' ' 

With  the  idea  of  obtaining  more  information  relative  to  the  chemical 
characteristics  of  the  common  California  white  wheats,  the  samples  dis- 
cussed previously,  as  well  as  some  others,  were  subjected  to  chemical 
analvsis. 


THE  METHODS  FOR  CEREAL  ANALYSIS. 


The  methods  of  analysis  adopted  for  this  work  were  adapted  from  those  given  in 
Bulletin  107.  of  the  Bureau  of  Chemistry,  United  States  Department  of  Agriculture, 
and  the  work  of  Teller,  and  are  set  forth  below. 

Moisture. — Dry  2  to  3  grams  of  the  material  for  five  hours  at  the  temperature  of 
boiling  water.  Use  the  aluminum  moisture  dishes  provided  for  this  purpose.  ( Note. — 
If  fat  is  to  be  determined  the  dried  material  from  the  moisture  determination  can  be 
used. ) 

Ash. — Char  2  grams  of  the  material,  if  a  wheat  meal,  or  3  grams  if  a  flour,  and 
burn  to  whiteness  at  the  lowest  possible  red  heat.  If  a  white  ash  can  not  be  obtained 
in  this  manner,  exhaust  the  charred  mass  with  water,  collect  the  insoluble  residue  on 
a  filter,  burn,  add  this  ash  to  the  residue  from  the  evaporation  of  the  aqueous  extract, 
and  heat  the  whole  to  a  low  redness  till  the  ash  is  white  or  nearly  so.  Great  care  has 
to  be  taken  with  these  wheat  products  not  to  overheat  at  the  start.  It  must  under 
no  circumstances  be  fused  if  phosphoric  acid  is  to  be  determined  in  the  ash,  other- 
wise fusing  is  allowable,  the  loss  being  so  small  as  to  be  negligible.* 

*  Leavitt  &  Le  Clerc,  "Loss  of  Phosphoric  Acid  in  Ashing  Cereals,"  Jour.  Am.  Chem. 
Soc,  Vol.  XXX,  No.  3,  p.  391. 

SCHEME  FOR   NITROGEN   DETERMINATION. 

The  basal  scheme  for  nitrogen  determination  for  various  protein  com- 
pounds is  as  follows : 

Determine    total    nitrogen x 

Determine  non-gluten  nitrogen  (=salt  soluble  X.  —  constant  *) y 

Difference  =  gluten  nitrogen =  x  —  y 

Determine  gliadin  nitrogen   (=alcohol  soluble)  f z 

Difference=glutenin  nitrogen =(# — y) — z 

*  Constant  for  soft  wheat  meals=.15. 
Constant  for  durum  wheat  meals  =  .20. 
Constant  for  flour=.22. 

Thes<-  constants  represent  the  average  amount  of  gliadin  nitrogen 
that  will  be  found  in  the  salt  solution. 

j-  Strictly  speaking,   the  gliadin   nitrogen  should  be  corrected  for  the  amid  nitrogen 
m.  bul    for  mosl   practical  purposes  this  may  be  neglect*'! 


Bulletin  212]  CALIFORNIA  WHITE  WHEATS.  345 

Detailed  Outline  of  Methods. 

Total  Nitrogen — Gunning  Method:  In  a  digestion  flask  (Kjeldahl) place  one  gram 
of  the  material  to  be  analyzed.  Add  10  g.  of  powdered  potassium  sulfate  and  about 
20  cc.  of  concentrated  sulfuric  acid.  Digest  as  in  the  ordinary  Kjeldahl  process, 
starting  with  a  comparatively  low  temperature  and  gradually  increasing.  Digest 
until  the  mixture  is  colorless.  Do  not  add  either  potassium  permanganate  or  potas- 
sium sulfid.  Dilute,  neutralize  and  distil  as  in  Kjeldahl  method.  In  neutralizing  it 
is  convenient  to  add  a  few  drops  of  phenolpthalein  to  serve  as  an  indicator. 

Use  10  cc.  n/4  hydrochloric  acid,  dilute  with  an  equal  volume  of  water  for  collect- 
ing the  ammonia  and  distil  off  about  three  fourths  of  the  contents  of  the  distillation 
flask.     Use  n/10  ammonia  for  titrating  back  the  acid,  with  cochineal  as  an  indicator. 


Note. — For  further  details  see  Official  Method,  Bui.  107,  page  7. 

(2)  Total  Proteids.     Nitrogen  determined  as  above  x  5.68  =  total  proteids. 

(3)  Gliadin.  Weigh  out  21  gms.  of  flour  into  a  small  flask  holding  somewhat 
more  than  lOOcc.  Add  100  cc.  of  70  per  cent,  alcohol  and  shake  thoroughly  for  15 
minutes.  Allow  to  stand  18  hours  and  filter  into  a  Kjeldahl  digestion  flask  with  a 
short  neck.  Wash  the  residue  with  100  cc.  of  70  per  cent,  alcohol.  Add  to  the  total 
filtrate  10  cc.  of  concentrated  sulfuric  acid  and  distill  off  the  excess  of  alcohol,  con- 
tinuing the  distillation  until  fumes  appear.  Add  10  cc.  more  of  concentrated  sulfuric 
acid  and  finish  the  determination  of  nitrogen  by  the  Gunning  method.  The  nitrogen  X 
5.68  =  proteid  soluble  in  alcohol. 

With  old  and  unsound  flours  a  correction  must  be  made  for  soluble  amid  bodies. 

(4)  Non-Gluten  Nitrogen.  Place  4  grams  of  the  material  in  a  200  cc.  flask.  Add 
about  15  cc.  of  a  1  per  cent,  solution  of  sodium  chlorid  and  shake  thoroughly.  To  the 
resulting  homogeneous  mass,  add  enough  of  the  same  solution  to  make  exactly  100  cc. 
of  the  salt  solution  as  a  total  amount.  Shake  the  contents  of  the  flask  in  a  shaker 
for  6  hours.  After  allowing  it  to  stand  over  night  to  settle,  filter  off  50  cc.  of  the 
liquid  through  a  12£  cm.  dry  filter,  pouring  back  the  first  portion  of  the  filtrate  until 
it  filters  clear  and  determine  the  nitrogen  therein  by  the  Gunning  method.  On  col- 
lecting this  50  cc.  with  a  few  cubic  centimeters  of  washings  in  a  Kjeldahl  flask  and 
adding  20  cc.  concentrated  sulfuric  acid,  the  water  can  readily  be  boiled  off,  especially 
if  the  flask  be  protected  from  the  naked  flame.  When  the  acid  ceases  to  foam  it  is 
cooled  slightly,  sulfate  of  potash  added  and  the  nitrogen  determination  completed  in 
the  usual  way.  After  adding  the  sulfate  of  potash,  the  time  required  for  the  diges- 
tion is  but  a  few  minutes. 

A  small  percentage  of  gliadin  nitrogen  will  be  included  in  the  above  determina- 
tion. Experience  has  shown  that  this  amounts  to  about  .15  per  cent,  for  white  wheat 
meals  and  is  quite  constant.  This  factor  (.15%)  should  be  subtracted  from  the 
nitrogen  per  cent,  as  determined  in  the  above  procedure.  For  factors  to  use  with 
other  wheats  see  page  344.  The  difference  is  called  Non-gluten  Nitrogen.  The 
protein  corresponding  to  this  nitrogen  is  calculated  by  multiplying  by  5.68. 

(5)  Glutenin.  For  most  purposes  the  difference  between  the  gluten  nitrogen  and 
the  gliadin  nitrogen,  as  determined  above,  may  be  considered  glutenin  nitrogen.  For 
more  accurate  work,  however^  the  glutenin  nitrogen  may  be  determined  as  follows : 

The  residue  from  the  gliadin  determination  is  washed  with  70  per  cent,  alcohol  until 
the  washings  no  longer  react  for  proteids.  Transfer  it  to  a  flask  and  add  200  cc.  of 
a  5  per  cent,  solution  of  sodium  chlorid  to  remove  globulin  and  other  proteids.  After 
two  hours  extraction  the  residue  is  washed  with  distilled  water  and  transferred  to  a 
flask,  250  cc.  of  a  2  per  cent,  solution  of  potassium  hydroxid  added  and  after  3  hours' 
extraction  the  solution  is  filtered  and  the  nitrogen  determined  in  200  cc.  of  the  filtrate 
in  the  usual  way. 

(6)  Amid  Nitrogen.  From  100  cc.  of  the  salt  extract  precipitate  all  the  proteids 
by  adding  10  cc.  of  a  ten  per  cent,  solution  of  phospho-wolframic  acid,  made  by  dis- 
solving the  pure  solid  in  distilled  water.  (Note.  In  case  of  bran,  it  may  be  nec- 
essary to  add  more  of  the  phospho-wolframic  solution.)  Allow  to  settle  before  filter- 
ing and  determine  the  nitrogen  in  the  clear  filtrate.  In  order  to  secure  a  clear  filtrate 
it  will  doubtless  be  necessary  to  allow  the  solution  to  stand  over  night  in  order  to 
obtain  a  clear  supernatant  liquid.  On  collecting  this  (50  or  100  cc.  with  a  few  cubic 
centimeters  of  washings)  in  a  Kjeldahl  flask  and  adding  20  cc.  of  concentrated  sul- 
furic acid  the  water  can  be  readily  boiled  off,  especially  if  the  flask  be  protected  with 
a  thin  sheet  of  asbestos.  When  the  acid  ceases  to  foam  it  is  cooled  slightly,  sulfate 
of  potash  added  and  the  nitrogen  determination  completed  in  the  usual  way.  After 
adding  the  sulfate  the  time  required  for  digestion  is  but  a  few  minutes. 

3— b212 


346  UNIVERSITY   OF    CALIFORNIA — EXPERIMENT    STATION. 

(7)  Edestin  and  Leucosin  Nitrogen.  To  50  cc.  of  the  clear  salt  extract,  obtained 
as  described  above,  add,  in  a  500  cc.  Kjeldahl  digestion  flask,  250  cc.  of  pure  94  per 
cent,  alcohol  (188  per  cent,  proof,  re-distilled).  Mix  thoroughly  and  allow  to  stand 
over  night.  Collect  the  precipitate  on  a  filter  (10  cm.)  of  good  quality,  return  to  the 
flask,  and  determine  the  nitrogen,  making  proper  correction  for  nitrogen  in  the  filter. 


Note. — If  desired  these  two  proteids  may  be  separated  by  coagulating  the  leucosin 
at  60  °C.  and  precipitating  the  edestin  by  adding  alcohol  to  50  cc.  of  the  clear  filtrate 
as  before.     The  nitrogen  in  each  precipitate  may  then  be  determined. 

(8)  Baker's  Sponge  Test. — 100  grams  of  flour  are  weighed  into  a  wide  porcelain 
dish  or  bowl.  A  part  of  the  water  (50  to  65  cc.)  necessary  to  make  a  stiff  dough  is 
run  in  from  a  burette.  In  this  is  dissolved  5  g.  of  sugar  and  5  g.  of  compressed  yeast. 
The  flour  is  then  stirred  in  with  steel  spatula  and  more  water  added  until  dough  of 
standard  stiffness  is  obtained.     Amount  of  water  used  for  dough  recorded. 

The  dough  is  now  placed  in  tubes  of  about  4  inch  diameter,  graduated  into  cubic 
centimeters.  These  tubes  are  now  set  in  water  at  90 °F.  and  the  dough  allowed  to 
rise.  It  must  be  constantly  watched  until  the  maximum  height  is  reached  and  the 
dough  falls,  when  the  time  required  to  rise  and  the  volume  in  cubic  centimeter  is 
recorded.     This  is  repeated  and  the  volume  and  time  again  recorded. 

By  dividing  the  volume  of  loaf,  to  which  100  grams  of  flour  rises,  by  the  percentage 
of  gluten  in  the  flour,  the  volume  of  loaf  produced  by  each  gram  of  gluten  is  found. 

(9)  Acidity. — In  a  porcelain  casserole  place  5  grams  of  flour,  and  gradually  mix 
with  about  50  cc,  of  distilled  water  freed  from  carbon  dioxid  by  previous  boiling. 
When  a  perfectly  homogeneous  mixture  has  been  obtained  add  a  few  drops  of 
phenolpthalein,  and  titrate  with  n/50  NaOH.  It  is  unnecessary  to  filter  previous  to 
titration.     Calculate  results  to  sulfuric  acid. 

(10)  Wet  Gluten. — Weigh  out  25  grams  of  the  sample,  moisten  with  15  to  18  cubic 
centimeters  of  water,  knead  to  a  stiff  dough.  Work  thoroughly  so  as  to  bring  all 
gluten  into  active  contact.  Allow  to  stand  for  one  hour.  Holding  the  mass  in  the 
hand  under  a  slow  stream  of  cold  water  gently  pull  and  knead  at  the  same  time  until 
the  starch  and  all  soluble  matters  are  washed  out.  It  is  well  to  conduct  the  work 
over  a  fine  sieve  to  prevent  the  loss  of  small  particles  of  gluten.  Then  place  in  cold 
water  and  allow  to  stand  for  one  hour,  finally  remove  from  the  water,  knead  well  in 
the  hands,  frequently  drying  the  hands  upon  a  towel.  During  the  kneading  of  the 
gluten,  manipulate  it  in  such  a  way  as  to  ultimately  bring  all  parts  of  the  gluten  on 
the  outside.  When  all  the  free  water  has  been  removed,  roll  the  mass  into  a  ball  and 
weigh  either  upon  a  counterpoised  card  or  in  a  flat-bottom  dish.  Note  should  be  made 
of  the  color  and  general  stiffness  as  shown  by  the  way  it  stands  up  upon  the  card. 
The  stiffer  the  gluten  the  more  globular  the  mass. 

(11)  Dry  Gluten. — After  weighing,  introduce  the  ball  of  wet  gluten  into  a  drying 
oven  at  a  temperature  of  boiling  water  and  try  to  constant  weight.  The  time  required 
will  be  not  less  than  fifteen  hours,  cool  and  weigh. 

(12)  Water  Capacity. — The  difference  between  wet  and  dry  gluten  equals  the 
water  holding  power.     Record  this,  as  one  part  gluten  holds  x  parts  of  water. 

(13)  Ether  Extract. —  (Fat)  Extract  from  2  to  3  grams  of  the  substance  used 
for  the  determination  of  moisture,  with  anhydrous  alcohol-free  ether  for  sixteen 
hours.  Filter  off  the  solid  residue  through  a  small  filter  paper  into  a  tared  flask. 
Distil  off  the  ether,  and  dry  the  extract  to  constant  weight.  This  work  is  most  con- 
veniently done  in  a  small  wide-mouthed  Erlenmeyer  flask. 

Or,  the  residue  can  be  collected  in  a  tared  Gooch  filter,  dried  as  in  the  moisture 
determination,  and  the  loss  in  weight  regarded  as  ether  extract. 


Note. — The  ether  used  for  this  work  must  be  strictly  anhydrous.  To  prepare  this, 
wash  any  of  the  commercial  brands  of  ether  with  two  or  three  successive  portions  of 
distilled  water,  and  add  solid  caustic  potash  or  soda  until  most  of  the  water  has  been 
abstracted  from  the  ether.  The  final  traces  of  moisture  can  be  removed  by  adding  to 
the  partially  dried  ether  carefully  cleaned  metallic  sodium,  cut  in  small  pieces,  until 
no  more  hydrogen  gas  is  evolved.  The  dehydrated  ether  should  be  kept  over  metallic 
sodium. 


Bulletin  212] 


CALIFORNIA   WHITE    WHEATS. 


347 


A  TRIAL  OF  THE  POLARISCOPIC  METHOD  POR  THE  DETERMINATION  Of  GLIADIN. 

The  use  of  the  polariscope  has  been  suggested  for  the  determination 
of  gliadin  in  cereal  products  as  offering  a  method  which  would  reduce 
the  time  required  by  the  ordinary  Gunning-Kjeldahl  operation,  and  at 
the  same  time  be  sufficiently  accurate  for  technical  purposes. 

With  the  idea  of  satisfying  ourselves  upon  the  applicability  of  the 
method,  as  applied  to  the  products  in  hand,  comparative  trials  of  this 
method  were  made  against  the  ordinary  Gunning-Kjeldahl  procedure. 

This  is  more  rapid  than  the  regular  method  and  is  recommended  for 
general  work  when  there  is  sufficient  material.  Weigh  out  15.97  grams 
of  the  material  and  digest  over  night  in  100  cc.  70  per  cent  alcohol. 

The  flask  should  be  agitated  thoroughly  at  intervals  of  one  half -hour 
for  a  period  of  two  hours.  Filter  to  a  clear  solution,  protecting  from 
evaporation  as  much  as  possible.  Polarize  in  a  220  mm.  tube.  The 
reading  will  probably  be  a  minus  one.  Correct  for  sugar  by  adding  to 
50  cc.  of  the  filtrate  sufficient  mercuric  chlorid  (concentrate  solution)  to 
precipitate  all  the  proteids :  Make  to  55  and  polarize  again. 

The  range  of  material  covered  by  these  trials  was  somewhat  differ- 
ent than  those  mentioned  in  the  original  article  by  Snyder.*  The  first 
series  of  analyses  were  made  upon  soft  wheat  meals.  The  results  are 
set  forth  below : 


Gliadin  nitrogen  calculated  to  dry  matter. 

Laboratory  number. 

By 

Polariscope 

method. 

By 

Gunning 
method. 

Difference. 

19 

0.72 
0.56 
0.46 
0.38 
0.42 
0.42 

0.54 

0.49 

4.40 

0.43 

0.44 

0.39 

0.43 

0.49 

0.64 

0.55(?) 

0.53  (?) 

0.50 

249 

+  02 

254 

-.03 

257 

-  02 

265 

-.01 

266 

-.02 

268 

0.39 
0.38 
0.49 
0.57 
0.39 
0.39 
0.49 

.00 

270 

-.05 

288 

.00 

290 

-.07 

313 

-.16 

322 

-.14 

326 

-.11 

The  above  determinations  were  made  upon  soft  white  wheat  meals. 
In  this  lot  of  samples  the  gliadin  determination  by  the  Gunning  method 
had  already  been  made  several  weeks  before  the  trial  of  the  polariscope 
method. 

Determinations  were  made  by  the  polariscope  method  on  the  basis  of 
the  changed  moisture  content  of  the  sample,  and  the  results  in  each  case 
calculated  to  dry  matter  for  comparison.     Further,  the  methods  were 


H.  Snyder  in  Jour.  Am.  Chem.  Soc,  Vol.  XIX,  Xo.   12. 


346 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION. 


operated  by  different  parties,  so  there  were  undoubtedly  introduced  into 
the  operation  greater  differences  in  the  manipulation  of  securing  solu- 
tion of  the  gliadin  than  if  the  two  operations  had  been  conducted  by  the 
same  person.  Notwithstanding  these  sources  of  error  it  will  be  noted, 
that  with  the  exception  of  Nos.  313  and  322,  concerning  which  there 
was  previously  existing  some  doubt  as  to  the  accuracy  of  the  original 
determination,  the  polariscopic  method  gave  results  which  are  within 
the  range  of  error  of  most  operations. 

The  above  results  not  being  quite  satisfactory,  the  comparison  of 
methods  was  carried  further  with  the  same  class  of  material,  the  sample 
operated  upon  in  the  one  method  being  ta'ken  from  the  same  solution  as 
in  the  other,  one  portion  being  used  for  polarization  and  another  treated 
by  the  Gunning  method.  The  solution  of  gliadin  in  these  trials  was 
effected  by  digesting  in  the  cold,  as  described  by  Snyder,  15.97  grams  of 
the  material  in  100  cc.  of  70  per  cent,  alcohol.  The  flask  was  shaken 
at  intervals  of  half  an  hour  for  two  hours,  and  left  overnight  before 
filtration.  Ten  cubic  centimeters  of  this  solution  were  used  for  treat- 
ment by  the  Gunning  method,  after  first  driving  off  the  alcohol  by  evap- 
oration. By  this  procedure  one  would  expect  somewhat  closer  results 
than  by  the  former. 


SOFT    WHEAT    MEALS. 

FLOUR. 

By 

By 

By 

By 

Polariscope 

Gunning 

Difference. 

Polariscope 

Gunning 

Difference. 

method. 

method. 

method. 

method. 

0.90 

0.91 

-.0! 

0.77 

0.75 

+  .02 

0.70 

0.69 

+  .01 

0.59 

0.57 

+  .02 

0.86 

0.90 

-  .04 

0.51 

0.48 

+  .03 

0.81 

0.75 

+  .06 

0.46 

0.43 

+  .03 

0.64 

0.63 

+  .01 

0.62 

0.55 

+  .07 

0.70 

0.70 

.00 

0.77 

0.70 

+  .07 

0.66 

0.69 

-  .03 

0.86 

0.84 

+  .02 

0.92 

0.94 

-  .02 

0.64 

0.69 

-  .05 

Average 

+0.04 

0.95 

0.94 
0.59 

+  .01 
-  .02 

0.57 

0.55 

0.60 

-  .05 

DUR 

JM    WHEAT    MEALS. 

0.73 

0.71 
0.60 

+  .02 
+  .02 

0.62 

0.62 

0.66 

-  .04 

0.84 

0.83 

+  .01 

0.53 

0.56 

-  .03 

0.77 

0.78 

-  .01 

0.90 

0.92 

-  .02 

0.95 

0.94 

+  .01 

0.88 

0.85 

+  .03 

0.70 

0.76 

-  .06 

0.81 

0.78 

+  .03 

0.66 

0.69 

-  .03 

0.70 

0.70 

.00 

0.75 

0.75 

.00 

0.73 

0.74 

-  .01 

0.79 

0.83 

-  .04 

0.77 

0.78 

+  .01 

0.59 

0.62 

-  .03 

0.62 

0.60 

+  .02 

0.81 

0.78 

+  .03 

0.59 

0.57 

+  .02 

0.61 

0.64 

.00 

0.64 

0.60 

-  .04 

0.64 

0.60 
0.58 

-  .04 

Average 

-0.02 

\\  < 

-0.03 

Bulletin  212]  CALIFORNIA  WHITE  WHEATS.  349 

In  but  three  cases  out  of  the  forty-five  last  stated  does  the  difference 
between  the  two  methods  exceed  0.05,  which  is  certainly  as  close  as  one 
can  expect  ordinary  technical  work  to  be  done,  and  as  between  two  sam- 
ples is  undoubtedly  within  the  limits  of  accuracy  of  sampling  large  lots. 

A  still  further  test  of  the  method  was  given  by  making  a  gliadin  deter- 
mination upon  a  gluten  flour  in  which  the  Kjeldahl  method  showed  3.32 
per  cent,  of  gliadin  nitrogen.  The  polariscopic  method  showed  3.45 
per  cent. 

Considerable  difficulty  was  experienced  at  the  outset  in  securing  a 
clear  solution  for  filtration,  but  this  was  finally  overcome  by  avoiding 
excessive  agitation. 

Snyder  remarks  that  in  the  case  of  flours  analyzed  by  him,  and  prob- 
ably grown  in  the  middle  west,  "the  combined  alcohol  soluble  carbohy- 
drates and  non-gliadin  proteins  of  the  alcoholic  solution  affect  the  polar- 
ization to  only  a  slight  extent, ' '  and  states  that  after  the  gliadin  protein 
was  precipitated  the  non-gliadin  rotary  bodies  showed  a  reading  of  less 
than  0.20  on  the  sugar  scale. 

In  our  experience  with  the  method  it  was  always  found  necessary  to 
make  two  polarizations,  the  first  on  the  original  solution,  and  the  second 
after  separating  the  protein  bodies  by  the  use  of  a  concentrated  solution 
of  mercuric  nitrate,  and  then  making  the  required  correction  to  give  the 
true  gliadin  reading. 

This  was  particularly  true  in  the  case  of  wheat  meals  where  the  aver- 
age difference  between  the  two  polariscope  readings  was  1.05  on  the 
sugar  scale  corresponding  to  0.21  per  cent,  on  the  gliadin  scale,  the 
range  of  differences  on  the  sugar  scale  being  from  0.08  to  2.75.  In  the 
case  of  flours,  unless  extreme  accuracy  is  required,  the  correction  could 
be  neglected  inasmuch  as  the  error  is  much  less,  not  exceeding  0.04  per 
cent,  of  the  gliadin  scale. 

The  writers  are  strongly  impressed  with  the  idea  that  the  method  is 
worthy  of  a  much  more  extended  use  than  it  has  so  far  had,  and  that  if 
precautions  are  taken  to  correct  for  the  eifect  of  other  optically  active 
bodies,  there  are  fewer  opportunities  for  error  than  with  the  ordinary 
method  of  nitrogen  determination. 

NITROGEN   OF  COMPOUNDS  SOLUBLE  IN   ONE  PER  CENT.  SODIUM  CHL0RID 

SOLUTION. 

Before  reaching  a  decision  as  to  the  factor  to  be  subtracted  from  the 
nitrogen  found  in  the  salt  extract,  several  separations  of  the  nitrogenous 
ingredients  of  this  extract  were  made.  Teller  from  his  elaborate  work 
upon  this  point,  suggested  that  the  factor  .27  per  cent,  be  used,  and  pro- 
ceeded upon  that  basis.  In  discussing  this  question  he  states,  however, 
that  "two  other  samples  showing  an  unusually  low  difference  (that  is, 
gliadin  per  cent,  in  salt  extract.  G.  W.  S.)   are  white  wheats,  each  of 


350 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION. 


which  contains  a  very  low  per  cent,  of  gliadin. ' '  He  also  intimates  that 
another  factor  than  .27  might  be  preferable  for  such  wheats.  It  was 
with  the  idea  of  ascertaining  what  this  factor  should  be  that  the  sep- 
aration of  the  protein  compounds  was  undertaken. 

The  procedure  followed  was  as  set  forth  under  the  portion  of  this 
bulletin  headed  "Methods  of  Analysis  of  Cereal  Products." 

First  of  all,  to  ascertain  the  effect  of  different  methods  of  shaking  to 
secure  solution  of  the  compounds,  comparative  trials  were  made  (1)  by 
shaking  at  intervals  of  half  hours  for  a  period  of  six  hours,  and  (2)  shak- 
ing in  a  mechanical  shaker  continuously  for  a  period  of  six  hours,  the 
results  are  given  in  detail  in  the  following  table : 

TABLE  VIII. — SHOWING  NITROGEN  COMPOUNDS   IN  WHEAT  MEALS 
SOLUBLE  IN  ONE  PER  CENT  SODIUM-CHLORID  SOLUTION. 


Hard  Wheat  Meals. 

2 

c 

s 

a 

How  Treated. 

c 
3 

o 

2. 

3 
w 

3 

g,  (6 

3 

d 
to 

s 

2 
B.  £' 

3    3 

2 

0 

IS? 

723 
723 

Shaken  at  intervals  for  6  hours 

Shaken  continuously  for  6  hours— 

11.07 
11.07 

.43 
.53 

.17 
.21 

.06 
.06 

.20 
.26 

.224 
.291 

724 
724 

Shaken  at  intervals  for  6  hours 

Shaken  continuously  for  6  hours__ 

10.70 
10.70 

.49 
.53 

.17 

.24 

.07 
.06 

.25 
.23 

.280 
.257 

727 
727 

Shaken  at  intervals  for  6  hours 

Shaken  continuously  for  6  hours__ 

10.61 
10.61 

.42 
.49 

.22 
.20 

.06 
.06 

.14 
.23 

.159 
.257 

728 
728 

Shaken  at  intervals  for  6  hours 

Shaken  continuously  for  6  hours__ 

10.56 
10.56 

.46 
.51 

.23 
.20 

.06 
.07 

.17 
.24 

.190 
.269 

731 
731 

Shaken  at  intervals  for  6  hours 

Shaken  continuously  for  6  hours__ 

10.40 
10.40 

.48 
.52 

.20 
.21 

.08 
.07 

.20 
.24 

.223 
.269 

735 

735 

Shaken  at  intervals  for  6  hours 

Shaken  continuously  for  6  hours.- 

10.70 
10.70 

.45 
.51 

.21 
.20 

.08 
.06 

.16 
.25 

.179 
.280 

Average   at  6-hour  intervals 

Average  continuous  shaking 

10.67 
10.67 

.45 
.51 

.20 
.21 

.07 
.06 

.19 

.24 

.209 
.270 

Soft  Wheat  Meals. 


232  Shaken  at  intervals  for  6  hours.— 

232  Shaken  continuously  for  6  hours. 

237  Shaken  at  intervals  for  6  hours— 

237  Shaken  continuously  for  6  hours. 

240  Shaken  at  intervals  for  6  hours— 

240  Shaken  continuously  for  6  hours. 

242  Shaken  at  intervals  for  6  hours— 

242  Shaken  continuously  for  6  hours. 

245  Shaken  at  intervals  for  6  hours— 

245  Shaken  continuously  for  6  hours. 

Shaken  at  intervals  for  6  hours— 

246  Shaken  continuously  for  6  hours. 


Average  at  intervals  for  6  hours. 
Average  continuous  shaking 


11.42 
11.40 

.41 
.35 

.16 
.14 

.08 
.07 

.17 

.14 

11.52 
11.49 

.39 
.39 

.17 
.14 

.08 
.08 

.14 
•17 

11.85 
11.90 

.35 

.42 

.15 
.18 

.07 
.08 

.13 
.16 

11.36 
11.32 

.46 
.48 

.17 
.18 

.08 
.07 

.21 
.23 

10.73 
11.75 

.43 
.42 

.17 
.15 

.07 

.07 

.19 

.20 

10.70 
10.75 

.35 
.41 

.15 
.18 

.05 
.07 

.15 
.16 

10.27 
11.43 

.40 
.41 

.16 
.16 

.07 

.07 

.16 

.18 

.191 
.158 

.158 
.192 

.147 
.181 

.236 
.259 

.212 
.226 

.160 
.179 

.187 
.199 


Bulletin  212] 


CALIFORNIA   WHITE    WHEATS. 
Soft   Wheat  Flours. 


351 


2 

a 

H 

- 

> 

g 

o 

c 
B 

s* 

How  Treated. 

2. 

en" 

i 

E 

3 

_  ~ 

—  J- 

CD 

B.  I 

a 

•Oft 

19,24 

Shaken  at  intervals  for  6  hours 

10.99 

.36 

.12 

.03 

.21 

.235 

19,24 

Shaken  continuously  for  6  hours.. 

10.99 

.36 

.10 

.04 

.22 

.250 

248 

Shaken  at  intervals  for  6  hours 

11.35 

.36 

.12 

.03 

.21 

.237 

248 

Shaken  continuously  for  6  hours__ 

11.35 

.36 

.11 

.03 

.22 

.249 

266 

Shaken  at  intervals  for  6  hours 

11.25 

.31 

.09 

.03 

.19 

.214 

266 

Shaken  continuously  for  6  hours.. 

11.25 

.31 

.08 

.03 

.20 

.226 

268 

Shaken  at  intervals  for  6  hours 

11.13 

.29 

.09 

.02 

.18 

.202 

268 

Shaken  continuously  for  6  hours.. 

11.13 

.31 

.08 

.03 

..20 

.225 

288 

Shaken  at  intervals  for  6  hours 

10.40 

.36 

.12 

.03 

.21 

.245 

288 

Shaken  continuously  for  6  hours.. 

10.40 

.38 

.10 

.03 

.25 

.279 

512 

Shaken  at  intervals  for  6  hours 

10.70 

.41 

.12 

.02 

.27 

.302 

512 

Shaken  continuously  for  6  hours.. 

10.70 

.41 

.13 

.04 

.24 

.272 

Average  at  6-hour  intervals 

10.97 

.35 

.11 

.03 

.21 

.237 

Average  for  6  hours  shaking 

10.97 

.35 

.10 

.03 

.22 

.250 

General  average,   intervals 

10.64 

.40 

.16 

.06 

.19 

.211 

General  average,  continuous 

10.64 

.42 

.16 

.05 

.21 

.239 

An  examination  of  this  table  shows  that  the  continuous  shaking  would 
have  given  slightly  higher  results,  but  they  would  not  have  been  mate- 
rially changed  by  such  procedure,  and  so  far  as  the  general  run  of  tech- 
nical work  is  concerned  the  interval  shaking  is  doubtless  entirely  satis- 
factory. 

Adopting  as  the  basis  of  the  work  the  classification  of  the  proteids  of 
wheat  as  previously  set  forth7  a  nextract  was  obtained  from  4  grams  of 
finely  ground  wheat  meals  by  means  of  a  1  per  cent,  sodium  chlorid 
solution  and  aliquot  portions  used  for  the  direct  determinations  of  total 
nitrogen,  edestin  and  leucosin  nitrogen,  and  of  amid  nitrogen.  The 
difference  between  the  sum  of  these,  and  the  total,  was  presumed  to 
represent  gliadin  nitrogen  that  had  been  dissolved  by  the  salt  solution. 
Throughout  this  work  the  shaking  was  done  at  intervals  of  a  half  hour 
for  a  period  of  six  hours. 


352 


UNIVERSITY    OF    CALIFORNIA — EXPERIMENT    STATION. 


TABLE   IX.— SHOWING   NITROGEN    OF   COMPOUNDS    SOLUBLE   IN    ONE    PER 
CENT  SODIUM  CHLORID  SOLUTION. 


2 

o 

H 

H 

el 

0 

Q 

1 

1 

p 

5-  ®  u> 

5"  o. 

3  3  & 

Name. 

c 
3 
j 

i 

2. 

P 

l^5 

0  O 

1  W     m 

1      ^   8° 

i    •*  s 
i     3  & 

i 

I5" 

I  £ 

To? 

1 

205 
205 


206 
206 


212 
212 


231 
231 


232 
232 


233 
233 


237 
237 


242 
242 


245 
245 


240 
240 


Wheat  meal 
Wheat  meal 
Average   


Wheat  meal 
Wheat  meal 
Average   — 


Wheat  meal 
Wheat  meal 
Average  


Wheat  meal 
Wheat  meal 
Average   


Wheat  meal 
Wheat  meal 
Average   


12.00 
11.89 
11.945 

12.28 
12.21 
12.245 

11.63 
11.55 
11.59 

11.85 
11.68 
11.765 

11.42 
11.37 
11.395 


Wheat  meal 11.66 

Wheat  meal  ._ _„  11.84 

Average   11.75 

Wheat  meal 11.52 

Wheat  meal 11.46 

Average   11.49 

Wheat  meal _ 11.36 

Wheat  meal 11.28 

Average   ___ 11.32 

Wheat  meal  .__ 10.73 

Wheat  meal 10.77 

Average   10.75 

Wheat  meal  __  11.85 

Wheat  meal 11.95 

Average   11.90 


246     Wheat  meal 10.70 

246  Wheat  meal  .__ 10.81 

Average  ___ 10.755 

247  I  Wheat  meal  11.30 

247  Wheat  meal 11.54 

Average  11.42 

248  Wheat  meal 11.02 

248  Wheat  meal 10.97 

Average  10.995 

249  Wheat  meal  11.10 

249     Wheat  meal 10.95 

Average   11.025 


254 
254 


Wheat  meal  11.02 

Wheat  meal  10.66 

Average   10.84 

Grand  average  soft  wheat  meals__  11.41 


.35 
.37 
.36 

.38 
.37 
.375 

.46 
.45 
.455 

.36 
.39 
.375 

.41 
.38 
.395 

.46 

.48 
.47 

.39 
.41 
.40 

.46 
.46 
.46 

.43 
.42 
.425 

.35 
.34 
.345 

.35 
.35 
.35 

.41 
.39 
.40 

.35 
.36 
.355 

.34 
.35 
.345 

.35 
.34 
.345 

.39 


.16 
.16 
.16 

.17 
.17 
.17 

.17 
.17 
.17 

.17 
.17 

.17 

.16 
.14 
.15 

.20 
.20 
.20 

.17 
.19 

.18 

.17 
.17 

.17 

.17 
.17 
.17 

.15 
.15 
.15 

.15 
.14 

.145 

.15 
.14 
.145 

.15 
.12 
.135 

.14 
.13 
.135 

.12 
.12 
.12 

.16 


.08 
.08 
.08 

.10 
.10 
.10 

.15 
.16 
.155 

.06 
.07 
.065 

.08 
.10 
.09 


.09 

.09 


.09 
.085 

.08 


.07 
.07 
.07 

.07 
.07 
.07 

.05 
.06 
.065 

.06 
.06 
.06 

.04 
.05 
.045 

.05 
.06 
.055 

.05 
.05 
.05 

.076 


.11 
.13 
.12 

.11 
.10 
.105 

.14 
.12 
.13 

.13 
.14 
.135 

.17 
.13 
.15 

.17 
.18 
.175 

.14 
.13 
.135 

.21 
.19 
.20 

.19 
.18 
.185 

.13 
.12 
.125 

.15 
.15 

.15 

.20 
.19 
.195 

.16 
.19 
.175 

.15 
.16 
.155 

.18 
.17 
.175 

.154 


Bulletin  212] 


CALIFORNIA    WHITE    WHEATS. 


353 


TABLE  IX   (continued.) 


t 

1  ~S 

i    a  a 

| 

I     1 

.45 

.19 

.06 

.20    ! 

.43 

.17 

.06 

.20 

.44 

.18 

.06 

.20 

.43 

.19 

.06 

.18 

.43 

.17 

.06 

.20 

.49 

.17 

.07 

.25 

.42 

.22 

.06 

.14 

.46 

.23 

.06 

.17 

.48 

.22 

.07 

.19 

.48 

.20 

.08 

.20    ' 

.45 

.21 

.08 

.16 

.45 

.201 

.066 

.189 

.36 

.12 

.03 

.21 

.36 

.12 

.03 

.21 

.31 

.09 

.03 

.19 

.29 

.09 

.02 

.18 

.36 

.12 

.03 

.21 

.41 

.12 

.02 

.27 

.39 

.13 

.02 

.24    ! 

.354 

.11 

.025 

.215 

-.  -  - 


II 

— 

I    S  ? 

i 


721 
721 

722 
723 
724 
727 
728 
729 
731 
735 

19,24 
248 
266 
268 
288 
512 
513 


Hard  wheat  meal 

Hard  wheat  meal 

Average   

Hard  wheat  meal 

Hard  wheat  meal 

Hard  wheat  meal 

Hard  wheat  meal 

Hard  wheat  meal 

Hard  wheat  meal 

Hard  wheat  meal 

Hard  wheat  meal 

Grand  average  hard  wheat  meals. 

Flour  

Flour  ^ 

Flour  

Flour  

Flour  

Flour  

Flour  

Grand  average  flour 


10.71 
10.71 
10.71 
10.78 
11.07 
10.70 
10.61 
10.56 
10.46 
10.40 
10.70 
10.66 
10.99 
11.35 
11.25 
11.13 
10.40 
10.70 
10.90 
10.97 


.223 

.223 

.223 

.201 

.224 

.28 

.159 

.190 

.212 

.223 

.179 

.20 

.235 

.237 

.214 

.202 

.245 

.302 

.266 

.243 


From  these  results  it  was  decided  to  use  the  factor  .15  per  cent,  as 
representing  more  nearly  the  gluten  constituents,  which  pass  into  the 
salt  solution  in  the  treatment  of  soft  wheat  meals,  than  the  one  suggested 
by  Teller,  in  the  case  of  the  so-called  hard  wheats.  The  other  work 
indicates,  however,  that  a  somewhat  higher  factor  should  be  used  for  the 
hard  winter  and  durum  wheats,  and  a  still  higher  factor  for  flours.  The 
markedly  higher  factor  for  flours  undoubtedly  is  brought  about  from 
their  finer  condition.  Even  here,  however,  the  factor  appears  to  be 
lower  than  that  suggested  by  Teller  (.27),  for  in  but  one  case  out  of  the 
entire  number  did  the  figures  rise  as  high  as  that. 


DISCUSSION  Of  ANALYSIS  Of  WHOLf  WHfAT. 


Previous  to  analysis  the  samples  were  all  held  in  the  storeroom  under 
uniform  conditions  for  several  weeks  to  secure  greater  uniformity  in 
moisture  condition.  Each  sample  was  freed  from  all  foreign  matter, 
such  as  weed  seed,  chaff,  pieces  of  straw,  dirt,  etc.,  previous  to  being 
ground  to  a  fine  meal  for  analysis.  The  analysis  of  plump  kernels  only 
is  recorded  in  these  tables  and  in  this  respect  the  samples  are  strictly 
comparable.  For  the  better  comparison  of  results  all  the  chemical  data 
has  been  calculated  to  the  basis  of  dry  matter,  but  the  percentage  of 
moisture  in  the  original  is  recorded  in  each  case. 

It  is  of  particular  interest  in  the  first  place  to  compare  the  several 
varieties  one  with  another.  At  the  bottom  of  each  table  of  varieties  is 
given  the  average  for  each  of  the  respective  varieties.  The  averages 
are  also  set  forth  in  a  separate  table  (Table  XIV). 


354 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION. 


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Bulletin  212] 


CALIFORNIA    WHITE    WHEATS. 


355 


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356 


UNIVERSITY   OF    CALIFORNIA — EXPERIMENT    STATION. 


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Bulletin  212] 


CALIFORNIA   WHITE    WHEATS. 


357 


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CALIFORNIA   WHITE    WHEATS. 


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CALIFORNIA   WHITE   WHEATS. 


361 


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362  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION. 

The  first  thing  which  is  apparent  from  this  table  of  averages  is  the 
much  larger  moisture  content  for  these  wheats  than  is  usually  stated 
for  wheats.  In  fact  the  variety  tables  show  quite  a  range  in  moisture, 
all  the  way  from  a  maximum  of  14.17  in  No.  391  to  9.18  per  cent,  in 
No.  196,  with  a  general  average  for  all  samples  of  12.11  per  cent.  This 
is  a  considerably  higher  figure  than  it  was  expected  to  find,  especially 
as  the  analyses  for  the  most  part  were  made  during  the  dry  season. 
Richardson,  as  an  average  of  310  samples  of  American  grown  wheats, 
gives  10.50,  and  in  these  samples  there  is  also  a  wide  difference  between 
individual  samples,  viz.,  from  7.1  per  cent,  to  14  per  cent. 

In  the  case  of  results  here  stated  wherever  there  seemed  to  be  any 
question,  the  work  was  checked  by  a  duplicate  determination.  This 
generally  high  moisture  content  of  the  samples  may  perhaps  be  partially 
explained  from  the  fact  that  the  laboratory  is  situated  comparatively 
rear  the  bay  and  the  atmosphere  is  usually  quite  moisture-laden  even 
during  the  summer.  That  grain  absorbs  moisture  from  the  air  very 
readily,  has  been  shown  by  experiments  carried  on  at  this  Station  in 
bringing  grain  from  the  interior  sections  of  the  State  where  the  atmos- 
phere is  very  dry  to  the  coast  region.  Undoubtedly  this  fact  has  had 
much  to  do  with  producing  the  condition  here  shown. 

It  is  claimed  that  the  moisture  that  wheat  will  thus  absorb  during  a 
voyage  from  San  Francisco  to  Liverpool  will  sometimes  increase  its 
weight  enough  to  pay  the  entire  cost  of  freight  ( ? ) .  In  the  experiments 
above  indicated  it  was  shown  by  Dr.  Hilgard  that  wheat  from  the  inland 
portions  of  the  State  might  increase  as  much  as  25  per  cent,  by  absorp- 
tion of  moisture,  while  a  gain  of  5  to  15  per  cent,  may  be  looked  for  with 
absolute  certainty.  A  difference  of  9  per  cent,  was  observed  in  twenty- 
four  hours.  It  is  barely  possible  that  this  increased  moisture  content 
may  have  some  chemical  influence  upon  the  quality  of  the  gluten  which 
is  a  matter  that  will  be  again  touched  upon. 

As  to  protein  content  the  varieties  stand  in  the  following  order, 
Propo,  Bluestem,  Australian,  Sonora,  and  Little  Club.  This  is  the  more 
noteworthy  since  it  is  in  the  same  order  that  the  miller  would  probably 
class  these  wheats.  Thus  it  seems  that  a  determination  of  the  total 
protein,  or  what  amounts  to  the  same  thing,  the  total  nitrogen,  would 
serve  to  classify  the  varieties  in  a  very  general  manner  as  to  adaptability 
for  milling,  aside  from  their  physical  characteristics. 

In  310  analyses  of  American  wheats  compiled  to  1890,  the  protein 
content  (Nx6.25)  varied  from  8.1  to  17.2,  with  an  average  of  11.9  per 
cent,  in  samples  carrying  10.5  per  cent,  average  moisture  content,  which 
calculated  to  the  same  basis  of  dry  matter  and  factor  as  presented  in 


Bulletin  212]  CALIFORNIA  WHITE  wheat-.  363 

these  wheats  would  correspond  to  an  average  of  12.08  per  cent.  The 
analyses  here  shown  give  an  average  protein  content  of  the  white  wheats 
of  9.95  per  cent,  in  the  dry  matter,  or  about  2  per  cent,  lower  than  the 
general  average  of  the  common  wheats  of  the  country. 

The  gliadin  follows  the  same  order  as  the  total  protein.  The  glutenin. 
however,  does  not  follow  the  reverse  order,  without  a  variation  in  the 
order  of  arrangement  in  the  wheats,  owing  to  a  variation  of  the  non- 
gluten  proteids.  It  w^ill  be  seen  that  in  the  matter  of  non-gluten 
proteids  Bluestem  exceeds  the  others  quite  materially.  The  effect  of 
this  is  to  reduce  the  glutenin,  and  thus  to  displace  this  variety  from  the 
order  shown  by  the  total  protein.  The  gluten,  chemically  determined, 
runs  in  the  same  direction  as  the  total  protein,  which  would  necessarily 
follow  unless  the  non-gluten  proteids  were  unduly  large  and  the  differ- 
ence in  gluten  between  any  two  varieties  very  small. 

Another  thing  which  appears  from  the  table  is  that  as  between  varie- 
ties neither  the  total  protein  nor  the  gliadin  bear  any  definite  relation 
to  the  size  of  the  kernels. 

Turning  attention  to  the  proportion  of  total  protein  of  wheats 
existing  in  the  form  of  gluten,  as  determined  chemically,  wTe  find  as 
follows : 

Bluestem 80.2  per  cent. 

White  Australian  82.9  per  cent. 

Little  Club 81.9  per  cent. 

Sonora    81.4  per  cent. 

Propo    82.3  per  cent. 

Average S.15  per  cent. 

There  is  shown  to  be  very  little  difference  in  the  ash  content  of  the 
varieties.  It  is  seen  that  the  ash  does  not  follow  the  size  of  the  kernel 
closely,  as  it  does  in  the  north  central  states,  nor  is  there  as  large  a  per- 
centage. In  a  general  way  it  follows  within  the  type,  but  the  partic- 
ular character  of  the  wheat  not  within  the  same  type  breaks  the  order 
in  this  regard.  Thus  a  Sonora  sample,  with  its  thin  bran,  which  part 
contains  the  larger  portion  of  ash,  carries  a  considerably  lower  per  cent 
than  does  a  Bluestem  sample  with  the  same  size  grains.  As  compared 
with  the  average  ash  content  of  the  United  States  wheats,  the  California 
grown  varieties  are  relatively  low. 

It  is  the  custom  to  consider  both  the  gliadin-glutenin  ratio  and  the 
gliadin  number  in  connection  with  flours  rather  than  the  whole  wheats, 
because  the  operation  of  milling  changes  the  relation  of  the  ingredients 
to  a  greater  or  less  extent,  but  since  it  is  highly  desirable  for  us  to  make 
certain  comparisons  of  grain  before  more  than  a  very  few  plants  can  be 
had,  and  since,  further,  it  was  desired  to  ascertain  what  was  the  result 


364  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION. 

of  milling  upon  this  ratio  in  the  case  of  the  common  white  wheats,  these 
data  are  also  calculated  for  the  whole  berry,  as  well  as  for  the  flour  later. 
To  either  the  miller  or  baker  it  will  have  its  greatest  significance  in  con- 
nection with  the  flour. 

Since  the  larger  part  of  the  gliadin  is  in  the  endosperm  of  the  grain 
the  milling  will  of  course  raise  the  gliadin  number  of  the  flour  above 
that  of  the  whole  wheat. 

While  Table  XIV  shows  an  appreciable  difference  between  one  variety 
and  another,  within  the  same  variety  there  is  even  a  greater  difference 
between  individual  samples  than  between  the  several  varieties,  as  will  be 
seen  by  referring  to  the  minimum,  maximum,  and  average  results,  as 
subjoined : 


Maximum 
protein. 

Minimum 
protein. 

Average 
protein. 

Bluestem  _ _ 

14.40 
13.42 
13.53 
15.80 
11.94 

7.15 
6.92 
7.38 
7.59 
8.97 

10.18 

White  Australian  __ 

9.89 

Little  Club  

Sonora    _      — 

9.35 
9.71 

Propo _         

10.64 

Australian,  for  instance,  shows  a  range  of  from  6.92  per  cent,  of  total 
protein  in  the  dry  matter  of  No.  232  to  13.42  per  cent,  in  No.  26. 

Very  generally  speaking  the  gliadin  seems  to  rise  and  fall  with  the 
total  protein,  but  there  seems  to  be  no  definite  or  absolute  ratio  between 
the  two.  This  is  also  in  accord  with  most  other  results  that  have  been 
published.  There  are  exceptions  even  to  this  statement  that  the  gliadin 
rises  and  falls  with  the  total  protein  in  whole  wheat ;  as  witness,  samples 
326  and  312,  the  former  carrying  10.48  per  cent,  total  protein  and  2.91 
per  cent,  gliadin,  and  the  latter  showing  but  7.97  per  cent,  total  protein 
but  rising  in  gliadin  content  to  3.77  per  cent.  Still,  while  individual 
instances  of  this  kind  do  occur,  it  may  be  said  that  in  general  the  gliadin 
does  follow  the  trend  of  the  total  protein  but  does  not  bear  any  definite 
ratio  to  it. 

The  same  statements  hold  concerning  the  other  varieties,  although 
Biuestem  appears  to  run  more  even  than  White  Australian.  Little 
Club,  while  generally  running  lower  in  protein,  has  certain  lots  which 
rank  very  high  in  this  group  of  compounds,  as  for  instance  Nos.  459, 
444,  6,  27,  and  29,  which  suggests  that  it  might  be  possible  to  fix  these 
clxir act eristics  to  a  certain  extent  at  least,  even  in  this  variety.     The 


Bulletin  212]  CALIFORNIA  WHITE  wheats.  365 

unreliability  of  this  variety  in  its  present  condition,  however,  has  given 
it  a  very  low  standing  among  millers. 

These  cases  of  unusually  high  protein  content  are  also  apparent  in  the 
other  varieties.  The  underlying  causes  of  such  wide  variation  are  not 
apparent  as  yet.  One  would  at  first,  perhaps,  assume  that  it  was  due 
to  soil  conditions  of  the  locality,  but  an  examination  of  the  record 
accompanying  each  sample  does  not  reveal  anything  definite  in  this 
direction. 

In  this  connection  it  is  interesting  to  record  a  series  of  analyses  of 
grain  taken  from  the  entire  product  of  individual  plants.  Each  of  the 
samples  used  for  the  analyses  stated  below  were  made  up  by  using  the 
grain  from  one  half  of  each  head  of  an  individual  plant.  Even  here, 
in  the  case  of  the  three  varieties  cited,  there  will  be  noted  the  great 
variation  between  individual  plants,  and  these  were  grown  under 
exactly  the  same  climate  and  as  near  as  possible  upon  the  same  char- 
acter of  soil.  The  variation  in  individual  plants  of  Australian  ranges 
from  a  minimum  of  9.06  to  15.31  per  cent,  total  protein,  or  a  variation 
of  6.25  per  cent,  within  25  plants,  and  the  range  in  Little  Club  is  even 
greater,  being  from  7.12  to  16.22.  Such  a  variation  as  here  appears 
among  individual  plants,  grown  under  the  same  conditions  of  soil  and 
climate,  would  seem  to  cast  grave  doubt  as  to  the  effect  of  climate  or  soil 
upon  the  composition  of  the  grain,  except  in  a  very  general  manner,  and 
to  throw  the  ultimate  causes  of  difference  within  the  plant  itself. 


366 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION. 


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Bulletin  212] 


CALIFORNIA   WHITE    WHEATS. 


367 


The  effect  of  seasonal  differences  in  the  grain  would  require  a  series 
of  analyses  covering  a  longer  period  than  is  here  represented,  but  it  is 
generally  regarded  that  these  do  have  a  greater  or  less  effect  in  causing 
a  fluctuation  of  the  entire  mass  for  any  one  season  as  compared  with 
another.  Below  are  presented  averages  of  the  previously  stated 
analyses  separated  according  to  the  years  in  which  they  were  grown. 

TABLE  XVI.— AVERAGE   COMPOSITION  AS  AFFECTED  BY   SEASON. 


Australian. 


Club. 


Bluestem. 


1904.       1905.       1904.       1905.       1904 


1905. 


Number  kernels  in  10  grams 
Relative  hardness  of  kernel 
Moisture  

Total  protein  

Gliadin  

Glutenin    

Gluten  

Non-gluten  protein  

Carbohydrates  and  fat 

Ash   


287 

286 

11.71 

10.38 
3.95 
4.58 
8.53 
1.85 

87.42 

2.00 


283        342 

327        212 

12.42     11.86 


297        281 

222        249 

12.13     11.81 


8.90 
3.19 
4.08 
7.27 
1.63 


9.43 
3.59 
3.96 
7.55 
1.88 


9.36 
3.13 
4.71 
7.84 
1.52 


10.47 
4.05 
4.23 

8.28 
2.18 


89.08  ■■  88.58 
2.02       1.99 


58.72     87.47 
1.92       2.06 


280 

328 

11.62 

9.12 
3.00 
4.70 
7.70 
1.41 

88.93 

1.95 


It  appears  from  these  averages  that  the  season  of  1904  had  a  tendency 
to  produce  a  smaller  kernel,  and  one  of  somewhat  higher  total  protein 
than  did  the  season  of  1905,  and  that  this  was  also  true  so  far  as  the 
gliadin  was  concerned,  but  that  it  does  not  hold  with  reference  to  true 
gluten. 

It  is  undoubtedly  true  that  should  the  season  be  such  as  to  seriously 
arrest  the  development  of  the  grain,  and  thus  produce  a  pinched  kernel, 
then  it  results  in  a  markedly  higher  gluten  as  well  as  gliadin  content. 
This  is  shown  in  the  analyses  of  a  considerable  number  (82)  of  pinched 
wheat  samples  grown  in  the  same  years  as  the  samples  given  above,  the 
results  of  which  analyses  are  stated  in  Table  XVII. 


TABLE    XVII. 


-SHOWING   AVERAGE   COMPOSITION   OF   PINCHED   WHITE 
WHEATS. 


Chemical  analysis. 


Calculated    to    dry    matter. 


are. 

r3 


Club   (46)   

Australian  (17) 
Bluestem  (13)  . 
Sonora  (6) 

Average   (82)   _. 


405 
341 
366 
442 

388 


12.28 
11.59 
12.18 
12.12 

12.04 


9.79 
11.78 
10.60 

9.62 

10.45 


3.88 
4.83 
3.85 
3.68 

4.06 


39.63 
41.00 
35.27 
38.23 

38.5 


4.33 

44.23 

8.21 

1.56 

4.95 

42.02 

9.78 

2.00 

4.96 

47.84 

8.81 

1.97 

3.76 

39.08 

7.44 

2.18 

4.50 

43.8 

8.56 

1.89 

2.11 
2.12 
2.02 

O  08 


368  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION. 


MILLING  TESTS. 


The  flour  used  in  making  our  ordinary  bread  is  the  white  portion 
called  the  endosperm  separated  from  the  remainder  of  the  kernel.  The 
whole  aim  of  the  miller  is  to  get  as  large  a  portion  of  this  white  material 
free  from  the  dust  hairs  and  small  particles  of  bran  (cuticle,  episperm, 
tegumen  ( ?)  and  embryonic  membrane  taken  together),  and  other  unde- 
sirable products  which  impair  the  color,  odor  or  quality  of  the  flour. 

To-day  there  are  probably  more  differences  in  mills  and  methods  of 
milling  than  ever.  To  mill  all  the  different  kinds  of  wheat  and  mill 
them  to  the  best  advantage  into  the  different  products  for  which  each 
wheat  is  best  adapted,  slightly  different  processes  must  be  employed, 
and  millers  do  not  agree  as  to  the  best  method  for  obtaining  certain 
ends,  nor  do  they  seem  to  think  it  urgent  that  a  standard  by  which  they 
mill  should  be  adopted.  Some  agitation  has  been  started,  however,  and 
it  is  hoped  that  some  satisfactory  standard  may  be  found.  As  the  sit- 
uation now  stands,  every  miller  makes  his  own  standard  and  determines 
the  quality  of  his  brand,  and  to  the  purchaser  the  name  is  meaningless. 

As  stated  above,  the  aim  of  the  miller  is  to  obtain  the  largest  possible 
yield  of  clear  white  flour.  This  is  accomplished  by  screening,  scouring, 
fanning,  and  washing  the  wheat,  as  may  be  deemed  necessary,  before 
grinding  it.  Washing  is  very  necessary  with  California  grown  wheats 
since  they  are  not  as  clean  as  eastern  grown  ones.  Then,  too,  the  native 
wheat  is  harvested  and  immediately  bagged,  in  which  condition  it  stays 
until  it  reaches  the  mill.  Not  only  do  they  contain  the  dry  dust  from 
the  dry  summer  fields,  but  also  smut  and  bunt  as  well  as  a  goodly  sup- 
ply of  grasshopper  segments ;  and  the  aroma,  after  two,  three  or  more 
months,  penetrates  the  seed  to  such  an  extent  that  it  is  noticeable  for 
some  time  after  it  is  emptied  from  the  bags.  Eastern  dealers  in  grain 
rarely,  if  ever,  find  this  condition,  but  instead  have  "musty  grain" 
which  is  caused  by  dampness.  Aeration  greatly  improves  musty 
wheats,  and  the  same  process  would  improve  the  above-stated  condition 
in  California. 

Having  cleaned  the  wheat  properly,  it  is  put  through  a  series  of  two 
to  six  corrugated  rolls  and  five  to  eight  sets  of  smooth  rolls,  the  number 
of  each  varying  with  the  process  used.  Between  each  set  of  rolls  the 
middlings  are  sized  and  separated  into  a  varying  number  of  streams,  so 
that  every  set  of  rolls  furnishes  a  stream  to  every  following  set  as  well 
as  some  portion  of  finished  product.  The  total  number  of  streams  pro- 
duced depends  entirely  upon  the  method  of  sifting  and  bolting. 


Bulletin  212]  CALIFORNIA  WHITE  WHEATS.  369 

The  corrugated  rolls  are  primarily  for  loosening  dust,  hairs,  and  the 
outer  portion  of  bran  layer.  No  attempt  is  made  at  grinding,  but  only 
at  cracking.  In  this  process  some  of  the  particles  of  flour  are  lost,  and 
this,  with  the  dust  and  other  loose  particles,  constitutes  the  low-grade 
flours.  The  amounts  lost  in  this  operation  depend  upon  the  condition 
and  quality  of  wheat  and  also  upon  the  skill  of  the  miller. 

After  the  removal  of  the  low-grade  flour  and  the  bran  portion,  the 
remainder  of  the  process  is  the  purification  and  reduction  of  the  mid- 
dlings into  the  higher  grades  of  flour.  Since  the  portion  near  the  bran 
has  a  higher  per  cent,  of  gluten  than  the  center  of  the  grain,  it  is 
obvious  that,  for  a  flour  with  high  gluten  content,  the  milling  must  be  as 
complete  as  possible  and  since  the  central  portion  is  the  first  to  be 
reduced  because  it  is  softer,  and  unprotected  after  the  grain  is  split, 
the  flour  from  the  first  breaks  contains  less  gluten  than  that  from  later 
reductions.  While  the  product  from  jthe  last  rolls  is  richest  in  total 
protein,  it  is  also  contaminated  with  particles  of  bran  and  a  small 
amount  of  germ,  which  lower  the  color  and  quality  of  the  flour  so  it 
can  not  be  included  in  the  patent  grades,  but  rather  in  the  clear  or 
bakers'  grade. 

Method  Pursued. — The  preparation  of  the  flour  was  made  on  a  small 
experimental  mill  with  two  sets  of  rolls,  one  with  medium  corrugations 
and  the  other  smooth.  The  sifting  was  done  in  an  attached  frame  carry- 
ing three  separate  bolting  cloths  or  wire  sieves,  as  was  necessary.  This 
frame  was  completely  enclosed,  and  the  pan  for  receiving  the  flour  was 
boxed  under  the  platform,  the  flour  being  conducted  from  the  shaker 
through  an  opening  in  the  platform  into  the  pan  by  a  canvas  stocking 
so  as  to  reduce  the  loss  from  dusting  to  a  minimum. 


370 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION. 


BRAN,    SHORTS,   AND   FLOUR. 

The  terms  flour,  shorts,  and  bran  are  rather  flexible  terms,  and  hardly 
capable  of  exact  definition,  and  for  this  reason  many  regard  the  stated 
yield  of  flour  as  having  relatively  small  value,  yet,  where  the  tests  are 
made  with  some  degree  of  uniformity,  the  mill  not  being  forced,  and 
only  that  portion  of  the  possible  flour  being  put  into  the  "straight" 
product,  which  can  be  so  done  without  reducing  the  color  standard,  it 
should  convey  a  meaning  of  relative  value.  It  is,  of  course,  perfectly 
easy  to  make  seventy  per  cent,  or  more  of  straight  flour  from  even  the 
lowest  grades  of  wheat,  provided  the  term  be  employed  in  a  sufficiently 
broad  sense  to  include  all  that  can  be  obtained  from  the  wheat,  and  a 
little  more  grinding  will  always  bring  a  little  more  of  the  bran  into  the 
shorts.  For  the  above  reasons  the  proportions  of  products  obtained  by 
different  operators  may  seem  to  vary  quite  widely,  and  the  same  varia- 
tion occurs  in  the  commercial  products,  particularly  in  what  is  com- 
monly called  "patent  flour,"  which  is  largely  dependent  upon  the  flex- 
ibility of  the  manufacturer's  conscience. 


Fig.  14. — Showing  small  grain  scourer  used. 
in   these  experiments. 

In  these  experiments,  before  grinding,  the  samples  were  cleaned  as 
thoroughly  as  possible  by  screening  and  passing  them  through  a  small 
sized  "Invincible"  scourer  designed  to  remove  all  dust  particles  and  the 
brush  upon  the  ends  of  the  kernels.  The  varieties  all  being  "soft" 
wheat,  it  was  not  deemed  necessary  to  "temper"  them  with  water,  as 
is  frequently  done.  Ordinarily,  the  grain  was  subjected  to  two  reduc- 
tions upon  the  corrugated  rolls,  although  in  a  few  cases  a  third  was 
deemed  necessary.  The  middlings  were  usually  reduced  in  three  oper- 
ationSj  more  were  required  in  a  few  instances. 

Flour.  Since  only  a  "straight  grade"  flour  could  be  made,  the 
material  was  all  passed  through  a  No.  10  bolting  silk,  and  care  was 
taken  to  include  in  this  all  the  material  which  seemed  by  its  color  to  be 
fit  for  lli«'  making  of  fair  quality  of  bread.     To  unify  the  product  it 


Bulletin  212' 


CALIFORNIA   WHITE    WHEATS. 


371 


was  now  passed  through  a  No.  11  bolting  silk,  and  all  that  passed  this 
silk  was  termed  flour.  The  part  retained  on  this  gauze,  when  judged 
to  be  clean,  was  termed  "low  grade."  The  flour  from  the  first  break 
was  not  dark  enough  to  be  necessarily  put  into  the  low  grade  class. 

Bran.— The  portion  of  the  chop  retained  on  a  2  mm.  mesh  wire  sieve 
was  termed  "bran." 

Shorts. — The  "shorts"  was  separated  from  the  middlings  by  a  No.  50 
and  a  No.  70  grit  gauze,  the  former  being  used  in  the  first  and  the  latter 
in  the  last  two  separations. 

In  each  case  a  kilogram  was  taken  as  the  basis  for  milling.  The  yield 
of  mill  products  is  stated  in  the  subjoined  table,  which  also  states  the 
bushel  weight,  the  condition  of  the  berry,  and  the  relative  ' '  commercial 


Fig.   15. — Small  Allis-Chalmers  mill  used  in  these  experiments. 

grading."  which  latter  was  obtained  by  taking  the  average  of  the 
grades  placed  upon  the  samples  by  the  "official"  grain  inspector  of  the 
Merchants'  Exchange  and  that  of  one  of  the  well  known  millers  of  the 
State,  on  the  basis  of  the  terms  "choice  milling,"  "good  milling."  "fair 
milling."  and  "poor  milling,"  and  allowing  a  difference  between  each 
term  of  2.5  points,  choice  milling  being  rated  as  100.  The  loss  due  to 
dusting  and  arising  from  transfers  of  material  ranging  from  zero  to 
three  per  cent.,  is  likely  to  belong  mostly  to  the  flour  and  for  the  sake 
of  uniformity  has  been  so  returned  (  ?). 


372 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION. 


Not  much  difference  could  be  noticed  in  the  reduction  of  the  various 
samples.  The  relative  hardness  of  some  could  easily  be  recognized, 
especially  if  two  samples  with  extremes  of  hardness  were  ground  one 
after  the  other.  There  was  an  appreciable  difference  in  the  bolting  of 
the  same.  Some  of  the  Club  samples,  as  millers  generally  recognize, 
required  more  time  to  obtain  the  same  separation,  but  some  also  bolted 
as  readily  as  either  Bluestem  or  Australian. 


TABLE  XVIII. — YIELD   OF  MILL   PRODUCTS. 
White  Australian. 


Bushel 
weight, 
pounds. 


63.0 
62.5 
62.5 
61.0 
60.5 
61.0 
60.5 
61.0 
59.5 
62.0 
58.9 


58.0 
57.5 
59.0 


63.0 
56.1 
60.0 


Condil.,.i  of  berry. 


Plump    

Plump   

Plump   

Plump   

SI.  pinched 

Plump   

Plump   

Plump   

Plump   

Plump   

Plump   

59.5  i  Plump   

59.5     Plump    

56.1  !  Pinched 

58.0  |  Plump   

Plump   

Pinched  

Plump   


Maximum 
Minimum 
Average   _ 


Relative 
grading. 


100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

98.7 

98.7 

97.5 

97.5 

97.5 

96.7 

96.7 

96.7 

92.5 

100.0 

92.5 

0.0 


Bran, 
per  cent. 


18.0 
18.0 
16.0 
16.5 
16.5 
16.5 
15.5 
17.0 
17.0 
18.0 
15.5 
16.0 
16.0 
15.5 
16.0 
18.0 
16.5 
16.0 

18.0 
15.5 
16.6 


Shorts, 
per  cent. 


11.5 
9.5 
14.0 
13.5 
12.9 
11.0 
12.0 
12.5 
12.5 
12.0 
12.5 
13.0 
13.5 
16.5 
14.5 
11.5 
13.5 
13.5 

16.5 
9.5 

12.8 


Flour. 


Straight. 


grade. 


69.0 

2.0 

70.5 

2.0 

68.0 

2.0 

68.0 

2.0 

68.7 

1.9 

70.0 

2.0  h 

70.5 

2.0 

68.5 

2.0 

69.0 

1.5  1 

68.0 

2.0 

70.0 

2.0 

68.5 

2.5 

68.5 

2.0 

66.0 

2.0 

67.5 

2.0 

68.5 

2.0 

68.5 

1.5 

68.0 

2.0 

70.5 

2.5 

66.0 

1.5 

68.7 

1.9 

.0 

.0 
2.0 

.8 
2.0 

.5 
1.0 

.0 
1.5 
1.0 

.5 

.5 
1.0 
1.0 
1.0 
1.0 

.0 

2.0 
.0 
.9 


Washington  BluestPin. 


62.0 
61.0 
60.0 
60.7 
59.0 
60.0 
59.0 
59.3 
59.5 
60.0 
59.5 
58.5 
58.8 
58.0 
58.0 
57.2 
56.5 

62.0 
56.5 
59.3 


Plump  

Plump  

Plump  

Plump  

SI.  pinched 
Pinched  ___ 
SI.  pinched 
Plump  ____ 
SI.  pinched 
SI.  pinched 
SI.  pinched 

Plump  

Plump  

M.  pinched 
SI.  pinched 
M.  pinched 
Plump    

Maximum  _ 
Minimum  _ 
Average   __ 


100.0 

16.5 

10.5 

70.5 

100.0 

17.0 

12.0 

69.0 

100.0 

16.0 

12.0 

70.5 

98.7 

19.0 

9.0 

70.0 

98.7 

16.5 

13.0 

68.5 

98.7 

15.5 

13.5 

69.0 

98.7 

15.5 

14.0 

67.5 

98.7 

16.0 

14.5 

67.5 

98.7 

17.0 

11.5 

69.5 

97.5 

16.0 

12.0 

70.0 

97.5 

15.0 

13.0 

70.0 

97.5 

16.5 

12.5 

69.0 

96.7 

18.0 

13.0 

66.5 

95.0 

17.5 

13.5 

67.0 

93.7 

19.0 

15.0 

64.0 

90.0 

17.0 

14.0 

67.0 

93.7 

18.0 

13.0 

67.0 

100.0 

19.0 

14.5 

70.5 

90.0 

15.0 

9.0 

64.0 

0.0 

16.8 

12.7 

68.5 

2.5 
2.0 
1.5 
2.0 
2.0 
2.0 
2.0 
2.0 
2.0 
2.0 
2.0 
2.0 
2.5 
2.0 
2.0 
2.0 
2.0 

2.5 
1.5 
2.0 


2.5 

3.0 

.5 

.0 

.5 

.5 

.5 

3.5 

.5 

2.0 

.0 

.5 

1.5 

.5 

2.0 

2.0 

1.0 

3.5 

.0 
1.3 


Bulletin  212] 


CALIFORNIA   WHITE    WHEATS. 
Little  Club. 


373 


5s 


Bushel 
weight, 

pounds. 


Condition  of  berry. 


.  Relative 
grading. 


Bran, 
per  cent. 


Shorts, 
per  cent. 


Straight. 


grade. 


163 

60.5 

233 

61.7 

266 

60.0 

253 

59.0 

28a 

57.5 

313 

58.0 

179 

60.2 

51a 

58.5 

185 

60.0 

317 

59.4 

277 

57.5 

305 

59.5 

169 

60.0 

50a 

58.5 

315 

59.0 

270 

54.5 

247 

54.0 

290 

57.8 

316 

55.0 

SI.  pinched 
Pinched  ___ 

Plump   

Plump   

Plump    

SI.  pinched 
SI.  pinched 
SI.  pinched 
SI.  pinched 

Plump   

Plump   

Plump   

M.  pinched 

Plump   

Plump    

Pinched  ___ 
SI.  pinched 
SI.  pinched 
Pinched  ___ 


97.5 

15.0 

14.5 

68.0 

2.0 

97.5 

16.5 

14.0 

67.5 

2.0 

96.7 

16.5 

12.0 

69.5 

2.0 

96.7 

18.0 

12.5 

67.5 

2.0 

96.7 

14.5 

13.5 

70.5 

1.5 

95.0 

17.0 

12.0 

69.0 

2.0 

95.0 

17.0 

14.5 

66.5 

2.0 

95.0 

16.0 

14.0 

68.5 

1.5 

93.7 

16.0 

15.0 

66.5 

2.5 

93.7 

16.5 

12.0 

70.0 

1.5 

93.7 

15.0 

14.5 

67.5 

3.0 

93.7 

17.0 

13.0 

68.0 

2.0 

93.7 

18.0 

14.0 

66.5 

1.5 

93.7 

16.0 

12.5 

69.5 

2.0 

92.5 

17.0 

13.0 

68.0 

2.0 

92.3 

18.0 

12.0 

69.0 

1.5 

92.5 

19.0 

14.0 

65.5 

1.5 

92.5 

17.5 

14.0 

67.0 

1.5 

90.0 

17.0 

11.5 

69.5 

2.0 

2.5 

1.5 

.0 

.0 

1.5 

.5 

2.5 

1.0 

.5 

1.0 

1.5 

.5 

.0 

.0 

.5 

1.0 

.0 

2.5 

.5 


Sonora. 


481 

254 

74 

249 
257 

248 


66.0 
63.7 
63.0 
62.8 
58.7 
59.0 


Plump   

Plump   

Plump   

Plump   

Plump   

SI.  pinched 


100.0 

11.0 

20.0 

66.0 

3.0 

98.7 

16.0 

13.0 

69.0 

2.0 

97.5 

9.0 

20.5 

68.5 

2.0 

97.5 

15.5 

14.0 

68.5 

2.0 

96.2 

16.0 

16.5 

65.0 

2.5 

85.0 

19.0 

14.0 

65.0 

2.0 

2.0 
1.0 
2.5 
1.5 
2.5 
1.0 


Propo. 


468 
225 
226 


62.8 
57.0 
53.0 


Plump   100.0 

SI.  pinched 95.0 

Pinched    I       90.0 


16.0 
11.0 
15.5 


12.5 

69.0 

2.5 

23.0 

64.0 

2.0 

20.0 

61.5 

3.0 

2.5 

.5 

1.5 


Examining  the  columns  recording  the  flour  yield,  there  appears  but 
small  difference  in  the  flour  yielding  power  o'f  the  three  principal  wheats, 
with  the  White  Australian  in  the  lead,  the  average  yield  being  68.7 
per  cent,  for  the  White  Australian,  68.5  per  cent,  for  the  Bluestem,  68.2 
per  cent,  for  the  Club,  and  67.0  per  cent,  for  the  small-grained  Sonora. 

The  greatest  difference  in  flour  yield  is  seen  to  be  8  per  cent.  This 
occurs  between  samples  No.  206,  which  yielded  only  62  per  cent,  and 
several  samples  each  yielding  70  per  cent.  Number  206  is  a  fairly 
plump  sample,  but  the  kernels  are  not  dense  and  the  weight  per  bushel 
is  only  58  pounds,  while  those  samples  which  yielded  70  per  cent,  flour 
averaged  about  61  pounds  per  bushel.  It  does  not  follow,  however,  as 
may  be  inferred,  that  those  wheats  weighing  heaviest  invariably  yield 
the  largest  amount  of  flour. 

In  the  yields  of  bran  and  shorts,  the  average  amount  obtained  is 
about  30  per  cent,  of  the  whole  wheat.     The  Sonora  wheat,  on  account 


374  university  of  California — experiment  station. 

of  its  smaller  size,  giving  a  larger  proportion  of  surface,  yields  a  larger 
percentage  amount  of  these  constituents.  The  bran  coat  is  actually 
thinner  on  this  type  than  on  the  other  three,  so  that  if  the  kernels  were 
as  large  as  those  or  Bluestem  it  would  undoubtedly  give  larger  flour 
yields. 

THE  BAKING  VALUE  OF  A  FLOUR. 

In  deciding  upon  the  baking  value  of  a  flour  there  are  three  points 
which  demand  particular  consideration,  viz.,  the  color,  the  gluten  con- 
tent, and  the  strength,  or  absorption  capacity,  all  of  which  points  must 
be  satisfactory  in  a  flour  of  the  best  quality  for  baking.  A  chemical 
analysis  alone  of  a  flour  tells  very  little  of  direct  value  to  a  baker,  as  it 
does  not  necessarily  indicate  the  character  of  the  loaf  which  that  flour 
will  produce,  but  if  the  baker  knows  the  gluten  content,  the  strength, 
and  the  color,  he  can  form  a  fairly  accurate  idea  as  to  how  the  flour 
will  act  in  baking.  In  addition  to  the  above,  there  are  certain  other 
characteristics  which  act  as  aids  in  enabling  one  to  have  a  better  under- 
standing of  a  flour.  In  general,  it  may  be  said  that  there  are  two 
classes  of  flours  as  to  their  effect  upon  the  touch.  One  type  may  be 
described  as  granular,  hard,  or  lively.  It  may  be  poured  from  one 
vessel  to  another  with  comparative  ease,  and  is  somewhat  suggestive  of 
an  extremely  fine  sand.  The  other  type  is  usually  referred  to  in  con- 
tradistinction as  soft,  velvety,  or  smooth.  It  is  this  latter  type  that  is 
obtained  from  the  milling  of  the  soft  white  wheats  here  under  discus- 
sion. Relatively  speaking,  the  latter  type  is  considered  weaker  than  the 
former  in  bread  value,  but  better  adapted  to  pastry,  biscuits,  etc.  This, 
however,  is  not  without  frequent  exception,  as  very  often  soft  wheat 
flours  may  be  found  to  have  excellent  baking  value  even  when  made 
without  blending,  as  will  be  seen  in  the  tabulation  later. 

Color. — One  of  the  most  important  characteristics  of  a  good  flour  is 
its  color.  While  mere  color  is  of  no  direct  benefit,  it  is  a  property  much 
desired,  and  one  by  which  the  relative  merits  of  flours  are  judged  to  a 
large  extent  by  millers,  brokers,  and  housewives  alike.  The  color 
depends  largely  upon  the  mechanical  composition  of  the  flour.  The 
poorer  the  process  of  milling  the  larger  the  amount  of  foreign  particles 
which  give  a  darker  color.  High  moisture  usually  has  a  darkening 
effect.  The  color  of  the  gluten  is  also  effective  in  varying  the  color  of 
the  flour. 

California  wheat  produces  a  very  white  flour  on  account  of  it  being 
very  starchy  and  having  a  small  amount  of  gluten,  which  is  not  so 
highly  colored  as  in  other  wheat  flours.  They  have  little  of  that  creamy 
color  so  characteristic  of  eastern  flours.  There  are  some,  however,  that 
are  quite  as  yellow,  and  in  the  Sonora  flours  examined  some  had  con- 
siderably  more  yellow  tint  than  the  eastern  flour  used  for  a  standard  of 
comparison. 


Bulletin  212]  California  white  wheats.  375 

In  the  washed  glutens  the  color  is  more  noticeably  variable  than  in 
the  flour.  For  the  most  part  these  glutens  are  blue  gray.  Occasionally 
there  is  a  creamy  one ;  generally  the  creamy-colored  flour  gives  a  creamy 
gluten,  but  a  creamy-colored  gluten  need  not  follow  from  a  creamy  flour. 
The  Sonoras  invariably  yielded  creamy  glutens.  The  whitest  flours  do 
not  necessarily  produce  the  whitest  loaves.  In  no  case  does  the  color  of 
the  bread  hold  the  same  relative  position  in  the  loaves  as  the  color  of 
the  flour.  In  a  general  way,  all  tinted  flours  are  a  little  darker  rela- 
tively when  baked,  as  their  color  value  does  not  increase.  The  yellow- 
tinted  flours  appear  to  change  their  relative  value  more  markedly. 

The  color,  however,  has  no  real  relation  to  the  baking  or  nutritive 
value,  and,  as  may  be  inferred  from  what  has  been  said,  is  not  a  very 
reliable  guide  as  to  the  color  of  the  resulting  loaf,  although  it  generally 
holds  that  gray  flour  produces  a  dirty-colored  loaf,  and  that,  inasmuch 
as  a  yellow  flour  usually  indicates  a  high  gluten  content,  they  usually 
show  less  loss  in  the  oven  and  therefore  have  a  better  bread  value,  and 
do  not  necessarily  produce  a  darker  loaf. 

The  matter  of  color,  while  it  certainly  does  affect  the  commercial 
value  of  a  flour,  is  a  decidedly  sentimental  factor.  It  is  also  noticed 
that  those  flours  which  enhance  their  color  value  in  the  process  of  bak- 
ing show  a  slightly  lower  loss  in  the  oven.  A  high  color  value  is  quite 
commonly  associated  with  low  gluten  and  low  strength. 

The  amount  and  quality  of  gluten  also  have  their  effect  on  the  color  of 
the  bread.  Those  flours  with  a  low  quality  of  gluten,  and  especially  if 
the  gluten  is  rather  dark,  produce  bread  that  appears  uneven  in  color. 
This  is  due  to  the  breaking  and  massing  of  the  gluten,  thereby  making 
uniform  distribution  of  the  gases  impossible,  and  preventing  uniformity 
in  color. 

In  carrying  this  comparison  to  the  dough,  it  is  seen  that  the  same 
relation  invariably  holds.  The  color  value  of  flours  from  this  class  of 
wheats  is  high  both  in  the  dough  and  in  the  flour.  The  relative  color 
value  between  the  flour  and  the  dough  made  from  it  is  not  expressed  in 
the  table,  because  of  the  lack  of  a  satisfactory  method  of  definite  state- 
ment of  this  factor,  but  the  dough  is  always  relatively  darker  than  the 
flour  from  which  it  is  made. 

As  to  the  relative  color  of  the  breads,  it  is  the  same  as  in  the  dough 
and  flour  with  the  exception  that  the  yellow  Sonora  flour  has  baked 
whiter  than  the  Club  flour,  which  is  probably  another  reason  why 
millers  do  not  like  Club  wheats. 

On  account  of  lack  of  time  and  the  somewhat  mixed  conditions  of 
these  commercial  wheats,  no  attempt  was  made  to  subject  them  all  to 
either  milling  or  baking  tests,  but  instead  selections  were  made  to  rep- 
resent as  wide  a  range  of  condition  as  possible.     Owing  then  to  the  com- 


376  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION. 

paratively  small  number  of  samples  baked,  no  attempt  will  be  made  to 
formulate  definite  statements  to  be  applied  to  the  several  varieties  when 
the  samples  are  pure.  This  must  come  from  a  later  study  now  in 
progress  in  which  the  varieties  are  of  known  purity.  An  inspection  of 
the  table,  however,  shows  a  number  of  interesting  points  which  will 
next  be  discussed. 

Inasmuch  as  the  calculation  to  dry  matter  would  not  change  the  rela- 
tive position  of  the  samples  in  any  case,  the  results  are  stated  on  the 
basis  of  the  original  condition  of  the  material. 

Moisture. — As  in  the  case  of  wheat,  the  moisture  content  of  flour  is 
largely  determined  by  the  atmospheric  conditions  under  which  it  is 
stored.  Around  the  bay  sections  of  the  State,  flours  would  show  a  much 
larger  percentage  of  moisture  than  would  those  of  the  same  grade  in 
the  interior,  and  likewise  their  absorption  capacity,  or  strength,  would 
be  somewhat  lessened,  provided  the  gluten  content  remains  the  same. 
From  a  commercial  standpoint  the  question  of  moisture  is  as  important 
in  the  case  of  flour  as  in  that  of  wheats  mentioned  earlier  in  this  bulle- 
tin. A  large  profit  it  undoubtedly  brought  to  dealers  through  the  influ- 
ence of  this  factor  alone. 

As  might  be  expected,  the  moisture  content  of  the  flour  is  invariably 
higher  than  that  of  its  corresponding  wheat. 

The  maximum  moisture  content  shown  in  any  of  these  flours  was 
14.13  per  cent,  and  the  minimum  11.32  per  cent.,  with  a  general  aver- 
age of  13.57  per  cent,  for  all  the  flours  examined.  These  are  very  high 
figures  as  compared  with  those  from  Canadian  flours,  which  are 
reported  as  carrying  from  9  to  10  per  cent,  and  Minnesota  flours  which 
carry  about  12  per  cent.  In  no  case  did  the  moisture  content  fall  as 
low  as  those  indicated  for  the  Canadian  flours,  and  in  three  instances 
it  rose  above  14  per  cent. 

To  a  certain  extent  this  difference  in  moisture  will  account  for  the 
difference  in  the  amount  of  bread  that  can  be  made  from  flours  produced 
in  those  sections  as  compared  with  the  Coast  flours.  This  same  will 
undoubtedly  apply  to  flours  in  the  interior  of  the  State  as  compared 
with  those  in  the  coast  section.  For  the  bread  maker  this  is  quite  an 
important  matter,  since,  other  things  being  equal,  the  drier  the  flour 
the  greater  the  weight  of  bread  that  can  be  made  from  it. 

Xitrogenous  Compounds. — It  was  observed  in  the  case  of  wheat  that 
the  total  per  cent,  of  proteids  was  low.  The  average  protein  content 
of  the  wheat  milled  was  8.57  per  cent,  and  the  average  of  the  flours 
milled  from  them  was  7.03  per  cent:  or  about  82  per  cent,  of  the  total 
protein  of  the  wheat  passed  into  the  flour.  Quite  generally  the  amount 
of  proteids  found  in  flour  depends  upon  the  amount  contained  in  the 
wheat,  though  it  does  not  follow  in  everv  case  that  the  wheat  with  the 


Bulletin  212]  CALIFORNIA  WHITE  WHEATS.  377 

highest  proteid  content  yields  a  flour  with  the  highest  percentage  of 
proteids. 

Total  Protein. — In  the  matter  of  total  protein  the  flours  take  the  fol- 
lowing rank:  Propo,  7.83  per  cent.;  White  Australian,  6.73  per  cent; 
Bluestem,  6.61  per  cent;  Little  Club,  6.59  per  cent;  Sonora,  6.39  per 
cent,  the  general  average  being  7.03  per  cent. 

As  to  the  proportion  of  protein  which  passed  into  the  flour  in  each 
variety  the  following  will  show  the  relation  by  varieties : 

White  Australian 80.2 

Bluestem    79.4 

Little  Club 84.4 

Sonora    85.1 

Gluten. — The  nature  of  gluten  has  already  been  discussed  in  the 
earlier  pages  of  this  bulletin  and  need  not  be  repeated  here.  The  per- 
centages set  forth  in  the  table  refer  only  to  the  chemically  determined 
gluten  consisting  of  the  gliadin  plus  the  glutenin. 

Considering  the  relation  of  gluten  to  total  proteids  in  wheats  and 
their  corresponding  flour,  the  average  relation  is  as  follows : 

Wheats.  Flours. 

White  Australian 83.9  96.1 

Bluestem   82.6  97.1 

Little  Club 77.0  98.6 

Propo _—  98.8 

Sonora 81.7  93.1 

The  relation  of  gluten  proteids  to  the  total  proteids  is  very  different 
in  these  flours  from  that  existing  in  the  common  wheats  of  the  Middle 
West.  Snyder  has  stated  that  the  best  bread-making  qualities  of  a 
flour  obtain  when  the  gluten  proteids  are  about  85  per  cent,  of  the 
total  proteids.  If  this  is  also  true  of  the  soft  wheats  then  we  may 
attribute  a  poor  quality  of  our  flour  in  part  at  least  to  the  unbalanced 
relation  of  gluten  to  the  total  proteids.  The  averages  for  each  type 
namely,  Bluestem,  97  per  cent;  Club,  97  per  cent;  Australian,  95  per 
cent. ;  Sonora,  95  per  cent. ;  show  how  far  different  this  relation  is 
from  that  found  in  eastern  wheat. 

The  quantitative,  wet-gluten  determination  was  carried  through  with 
a  considerable  number  of  the  flours,  but  the  results,  as  compared  with 
the  chemical  determinations,  were  so  inconsistent  that  they  will  not  be 
given. 

The  wet  gluten  as  determined  was  in  each  case  dried  and  the  per 
cent,  of  dry  gluten  determined.  These  figures  are  fairly  consistent  and 
reliable.  Subtracting  the  percentage  of  dry  gluten  from  100  gave  the 
per  cent,  of  moisture  held  by  the  gluten.  The  range  of  variation  was 
from  53.3  per  cent,  to  64.3  per  cent.  ( ?)  The  relation  between  the  moist- 
ure content  and  the  expansions  made  on  the  gluten  are  fairly  constant 
on  averages.  The  higher  the  amount  of  moisture  retained  by  the  wet 
gluten  the  larger  the  expansion.  In  a  general  way  the  expansion 
5— b212 


378  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION. 

fluctuates  with  the  amount  of  gluten.  There  are  certain  distinctive 
characteristics  of  these  soft  white-wheat  glutens  which  are  of  interest 
at  this  point. 

The  gluten  test  as  quite  generally  made  where  flour  is  studied  is  not 
at  all  satisfactory  when  applied  to  soft  wheat  flours.  The  first  diffi- 
culty encountered  in  its  application  is  the  small  amount  of  the  proteids 
contained  in  the  flour.  In  attempting  to  wash  a  flour  with  a  low  gluten 
content,  the  proportion  of  gluten  is  so  small  that  it  makes  it  almost 
impossible  to  get  the  fine  particles  into  contact  before  many  are  carried 
away  with  the  water. 

WASHED  GLUTEN  TESTS  NOT  RELIABLE. 

The  nature  of  the  gluten  is  a  second  difficulty.  It  acts  entirely  dif- 
ferent in  the  hand  from  eastern  flours.  The  first  difference  is  noticed 
in  the  dough ;  a  soft  wheat  dough  can  be  distinguished  very  easily,  espe- 
cially if  not  of  the  best  quality,  by  its  being  perfectly  smooth  on  the  sur- 
face after  the  dough  has  been  worked  and  is  ready  for  washing.  The 
standard  dough  is  soft  and  spongy,  while  the  soft  wheat  dough  is 
firmer  and  more  tenacious,  and  works  very  much  like  a  soft  putty.  The 
dough  on  being  worked  has  a  marked  tendency  to  stick  to  the  hands  and 
the  utensils.  The  standard  dough,  while  also  having  that  quality,  does 
not  have  it  to  the  same  degree.  The  two  doughs  differ  much  in  this 
respect,  that,  while  they  are  both  tenacious,  the  standard  dough  is  very 
cohesive  and  will  not  permit  its  body  to  separate  while  the  soft  wheat 
dough  will  in  nearly  all  cases.  Of  the  total  fifty-eight  doughs  made, 
only  three  or  four  approximated  the  standard  in  their  handling  qualities. 

The  next  noticeable  feature  these  doughs  present  is  in  the  surface  of 
the  doughs  when  placed  side  by  side.  The  poorer  dough  has  the 
smoother  surface.  The  better  the  quality  of  the  gluten  the  more 
uneven  is  the  surface.  There  are  no  abrupt  grooves  or  ridges  upon  it, 
but  there  are  small,  circular,  uneven,  bullet-like  prominences.  The 
further  in  the  process  this  dough  goes  the  more  pronounced  this 
becomes.  They  are  especially  noticeable  in  kneading  the  dough  back 
the  second  or  third  time.  On  a  poor-gluten  flour  this  structure  is  never 
seen,  not  even  in  kneading  back.  The  more  a  dough  is  worked  after 
raising,  the  less  noticeable  these  irregularities  become.  Their  appear- 
ance on  the  dough,  after  making  the  water-absorption  test,  generally 
i^ives  a  very  fair  idea  of  what  is  to  be  expected  in  the  volume  of  the  loaf. 

In  washing  a  poor  and  a  good  quality  of  gluten  from  flour  there 
appears  again  an  indication  of  the  relative  qualities  of  the  good  gluten 
dough,  the  gluten  masses  appear  distinct,  even  from  the  very  begin- 
ning, and  they  are  much  more  apt  to  stick  to  the  dough  ball  than  to  the 
hands.  The  standard  never  sticks  to  the  hands.  The  particles  may 
occasionally  be  separated  from  the  mass,  but  not  so  often  as  those  from 
the  poorer  gluten  doughs.     On  washing  a  dough  of  inferior  quality  the 


Bulletin  212]  CALIFORNIA  WHITE  WHEATS.  379 

gluten  masses  do  not  appear  as  soon ;  when  they  do  become  visible,  they 
are  not  distinct  and  clean,  but  mixed  with  more  starchy  paste.  This 
will  stick  to  the  hands  and  apparently  has  little  affinity  for  the  ball  of 
dough.  The  very  poorest  doughs  will  go  to  pieces  in  the  process,  and 
always  tend  to  form  a  paste  rather  than  a  separation,  and  it  makes  lit- 
tle, if  any,  difference  even  though  the  wash  water  be  used  drop  by  drop. 
A  good  washed  gluten  will  be  firm  and  very  much  like  gristle  at  first, 
but  will  work  down  after  awhile  to  a  very  elastic  and  well-mixed  mass. 
The  gluten  of  poor  quality  will  be  soft  and  indifferent,  and  soon  works 
into  a  smooth,  soft  mass  that  has  little  recoiling  ability,  and  when  placed 
upon  a  cardboard  to  dry,  if  it  is  not  dried  at  once,  it  is  very  likely  to 
run  all  over  the  cardboard,  thus  showing  its  low  strength. 

Considering  the  mechanical  separation  of  gluten,  as  applied  to  the 
soft  or  white  wheat  flour,  it  is  not  satisfactory,  as  stated  before.  In 
the  most  troublesome  instances  only  about  one  half  of  the  amount  was 
recovered.  This  leads  to  the  belief  that  perhaps  some  of  the  proteids 
of  these  wheats  are  partly  soluble  in  water  and  are  washed  away,  thus 
adding  to  the  mechanical  loss.  Some  flour  was  set  for  four  hours  in 
cold  water,  filtered,  and  the  nitrogen  in  the  filtrate  determined,  with  the 
result  that  from  12.48  to  17.90  per  cent,  of  the  total  proteids  were  found 
water-soluble.  As  was  previously  stated,  about  97  per  cent,  of  the  total 
proteids  in  flour  are  in  the  form  of  gluten.  Therefore,  some  of  the 
gluten  amounting  to  the  difference  in  these  two  percentages  must  be 
soluble  in  water.  The  alcohol  extraction  of  the  residue  showed  that 
from  25  per  cent,  to  58  per  cent,  of  the  gliadin  was  removed.  From 
samples  containing  small  and  large  amounts  of  gluten,  the  total  amount 
of  soluble  proteids  is  larger  in  the  high  gluten  flours  and  gradually 
falls  as  the  gluten  content  decreases.  The  decrease  in  the  soluble  pro- 
teids is  not  as  rapid  as  in  the  gluten  content,  so  that  the  percentage 
amount  of  soluble  proteids  to  the  total  amount  of  proteids  gradually 
increases  and  is  highest  on  the  flour  with  the  lowest  total  proteids,  thus 
tending  to  concentrate  the  error  in  the  method  upon  the  poorer  grade 
of  flour. 

Gliadin. — Gliadin  has  been  given  much  consideration  in  most  dis- 
cussions of  flour.  It  seems  hardly  worthy  of  so  much  stress  as  has  been 
given  it,  especially  as  regards  the  white  wheats.  The  gliadin  is  said  to 
impart  the  tenacity  and  adhesiveness  to  the  gluten.  While  this  may  be 
largely  true,  it  does  not  seem  to  apply  so  generally  to  the  white  wheats. 
The  total  average  of  gluten  in  the  form  of  gliadin  is  less  than  50  per 
cent.  The  standard  contains  53  per  cent.,  which  is  lower  than  is  usually 
found  in  eastern  spring  wheat  flours. 

There  is  a  very  decided  difference  in  the  tenacity  of  the  average  Cal- 
ifornia flour  gluten  and  the  standard;  the  Calif ornian  being  the  more 
tenacious  and  very  soft,  and  still  has  the  lower  amount  of  gliadin,  not 


380  UNIVERSITY   OF    CALIFORNIA — EXPERIMENT   STATION. 

only  as  figured  on  the  gluten,  but  those  that  are  figured  to  the  total 
amount  of  proteids,  and  contain  a  lower  percentage  than  the  standard 
on  the  same  basis. 

An  examination  of  the  table  shows  that  in  nearly  every  case  the 
gliadin  content  of  the  flour  is  higher  than  that  of  its  corresponding 
wheat,  and  that  this  difference  is  much  more  marked  in  the  wheats 
carrying  the  larger  per  cent,  of  protein. 

While  the  gliadin  increases  towards  the  outside  of  the  kernel,  there  are 
some  instances  in  which  the  reverse  appears  true,  which  may  be  inferred 
from  the  lower  percentage  of  gliadin  in  the  flour  than  in  the  wheat. 
In  one  sample  the  gliadin-number  in  the  wheat  and  in  the  flour  remains 
the  same.  Since  all  of  these  percentages  are  found,  they  would  sug- 
gest that  variations  in  every  way  in  the  distribution  of  the  gliadin  in 
the  grain  do  occur.  The  data  is,  however,  insufficient  to  fully  establish 
this  as  a  fact. 

Gliadin-N  umber. — By  the  gliadin-number  is  meant  the  percentage 
which  the  gliadin  is  of  the  total  protein. 

In  most  cases  the  gliadin-number  is  increased  in  milling,  that  is,  the 
flour  shows  a  larger  percentage  of  gliadin  than  the  corresponding  wheat, 
thus  showing  the  wheat  to  carry  a  larger  percentage  of  gliadin  in  the 
inner  portion  of  the  grain.  The  average  gliadin-number  for  these  sam- 
ples was  48.6  for  the  flours  as  against  33.4  for  the  wheats,  or  an  average 
increase  of  about  4  per  cent,  by  milling. 

The  range  in  gliadin-numbers  was  between  34.2  in  No.  268  and  69.3 
in  41a.  Considering  the  matter  by  varieties  Propo  leads  with  51.6. 
Were  the  gliadin-number  the  only  factor  which  should  be  considered  in 
relation  to  the  baking  value,  or  even  the  determining  factor,  then  Little 
Club  flour  with  an  average  of  51.6  should  stand  close  to  Propo,  but  that 
this  is  not  so  is  not  only  the  common  experience,  but  is  also  shown  in  the 
fact  that  the  average  volume  of  the  Club  loaves  was  only  76  cubic 
inches  as  against  83  and  85  cubic  inches,  respectively,  for  White  Aus- 
tralian and  Bluestem. 

That  the  effect  of  gliadin  ratio  may  often  be  overshadowed  by  the 
total  amount  of  gluten  is  clearly  shown  by  a  series  of  bakings  made 
from  flour  having  the  same  gliadin  ratio  (50:50),  but  a  varying  total 
gluten  content. 

The  gluten  content  of  the  flour  and  the  volume  of  each  resulting  loaf 
is  shown  below.     The  series  of  loaves  is  shown  in  Figure  No.  16. 

No.  Gluten.  Volume. 

8 10.11  97  cu.  in. 

9 9.37  87  cu.  in. 

10 6.92  83  cu.  in. 

11 5.50  66  cu.  in. 

12 4.70  61  cu.  in. 

Here  it  may  be  seen  that  notwithstanding  there  is  the  same  gliadin- 
n !i mlxr  the  volume  of  loaf  follows  the  order  of  the  totnl  protein. 


Bulletin  212] 


CALIFORNIA   WHITE    WHEATS. 


381 


382 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION. 


Loaves  per  barrel. 


Volume  of  loaf, 
cubic  inches. . 


Weight  of  loaf. 


Loss  in  baking,  per  cent. 


Absorption- 


Ash. 


Non-gluten 
protein... 


Gliadin 
number- 


Total 
gluten. 


Gliadin. 


Total 
protein. 


Moisture. 


Ash. 


Non-gluten 
protein 


Gliadin 
number. 


Total 
gluten. 


Gliadin- 


Total 
protein- 


Moisture. 


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384  UNIVERSITY   OF    CALIFORNIA — EXPERIMENT   STATION. 

BAKING  TESTS. 


A  number  of  the  flours  were  subjected  to  a  baking  test  to  obtain  a 
better  knowledge  of  the  actions  of  this  class  of  wheat  alone  in  the  oven 
for  the  sake  of  comparison  in  later  work. 

The  baking  test  furnishes  the  most  accurate  and  reliable  data  as  to 
the  relative  merits  of  flours.  The  bread  is  the  ultimate  product,  no 
matter  what  has  been  indicated  by  previous  tests.  Though  other  tests 
usually  assist  much  if  given  proper  consideration  and  value  in  enabling 
one  to  establish  right  relations  of  flours ;  the  baked  bread  is  the  one  way 
in  which  all  are  able  to  judge  of  a  flour  value ;  the  final  test  then  is  to 
decide  which  produces  the  better  bread  in  large  amounts. 

THE  METHODS. 

The  Strength  or  Water  Absorption. — The  strength  of  a  flour  is 
measured  by  its  water-absorbing  capacity  in  making  a  dough  of  given 
consistency.  It  is  a  factor  which  varies  considerably  with  different 
flours  even  from  the  same  variety  of  wheat.  It  is  of  much  importance 
in  determining  the  baking  value  of  a  flour. 

The  water-absorption  of  a  flour,  other  things  being  equal,  is  indicative 
of  the  amount  of  gluten  the  flour  contains  and  its  quality.  The  larger 
the  amount  of  the  gluten  or  the  better  quality  of  the  gluten,  generally 
speaking,  the  more  water  it  will  take  to  make  a  dough  of  certain  con- 
sistency. For  bakers,  a  flour  to  which  they  can  add  a  maximum  amount 
of  water  and  still  have  a  loaf  that  will  rise  well  and  present  an  even 
texture  and  good  color,  is  most  desirable.  The  larger  the  amount  of 
water  absorbed  by  a  flour,  the  more  loaves  can  be  produced  per  given 
weight  of  flour.  Since  the  relation  is  a  fairly  constant  one,  the  relative 
water-absorption  number  of  flours  compared  is  expressed,  with  other 
things,  by  the  number  of  one-pound  loaves  produced  per  barrel  of  flour, 
provided  the  comparison  is  made  under  like  conditions. 

A  peculiar  quality  very  noticeable  in  all  these  flours  is  that  of  the 
dough  becoming  soft.  There  is  constant  danger  of  adding  too  much 
water;  in  this  one  feature  the  California  flour  differs  from  the  standard 
flour  as  much  as  in  any.  Upon  this  depends  the  quality  of  the  bread 
more  than  any  other  one  factor.  If  there  can  be  a  reason  given  for 
this,  it  would  be  a  long  step  towards  explaining  the  whole  difference 
between  the  Pacific  coast  flour  and  flour  from  the  remainder  of  the 
continent. 

The  capacity  of  a  flour  for  holding  a  large  amount  of  water  in  the 
dough  bears  an  approximate  relation  to  the  total  per  cent  that  the  gluten 
protein  bears  to  the  total  protein.    The  larger  this  percentage  the  more 


Bulletin  212]  CALIFORNIA  WHITE  WHEATS.  385 

water  the  flour  will  absorb.  The  relation  also  extends  to  the  gliadin 
contained  in  the  gluten.  Two  flours  with  the  same  percentage  of  gluten 
usually  will  require  water  according  to  the  amount  of  gliadin  contained. 

The  Method. — The  water  absorption  or  "strength,"  is  determined  by 
making  a  standard  dough  from  a  flour  selected  as  a  standard  by  adding 
a  sufficient  amount  of  water  to  give  a  dough  of  rather  stiff  consistency. 
This  is  about  17.5  cc.  of  water  to  30  grams  of  flour  for  standard  spring 
wheat  flour,  and  16.7  cc.  for  winter  wheat  flour,  and  15.7  cc.  for  white 
wheat  flour,  when  made  to  the  same  consistency,  the  exact  amount  of 
water  required  is  noted.  From  this  can  be  calculated  the  necessary 
amount  of  water  for  any  given  amount  of  flour.  The  amount  here  used 
was  340  grams  of  flour  with  from  161  to  189  cc.  of  water.  To  this  was 
added  10  grams  of  fresh  compressed  yeast,  12  grams  of  sugar,  5  grams 
of  salt,  and  a  little  lard.  Two  thirds  of  the  flour  was  beaten  up  with  the 
water  for  ten  minutes,  the  remainder  of  the  flour  then  added  and  the 
whole  kneaded  for  ten  minutes  more.  The  yeast  was  previously  added  to 
the  measured  water  and  allowed  to  stand  for  fifteen  minutes  before 
being  mixed  with  the  flour.  All  utensils  and  apparatus  were  kept  at 
about  95°  Fahrenheit. 

On  removing  the  dough  from  the  kneader  it  was  made  into  two  small 
loaves  and  weighed  into  a  bread  pan  which  was  placed  in  an  electric 
cupboard  or  expansion  box  at  95 °F.  Here  it  was  allowed  to  rise  for  an 
hour  and  a  half,  re-kneaded  and  set  again.  When  the  dough  had  risen 
even  with  the  top  of  the  pan  it  was  at  once  placed  in  an  electric  oven  at 
400-425°  for  thirty-five  minutes.  After  cooling,  the  bread  was  weighed 
and  its  volume  taken  by  placing  the  bread  in  a  box  of  known  volume, 
filling  the  unoccupied  space  with  flaxseed,  and  measuring  the  seed 
required;  the  difference  in  the  volume  of  seed  and  the  volume  of  the 
box  giving  the  volume  of  the  loaf. 

TABULATION    AND    CALCULATION    OF    RESULTS. 

340  grams  of  flour  used. 

158  cc.  water  required  for  dough. 

10  grams  of  yeast. 

12  grams  of  sugar. 
5  grams  of  salt. 

525  grams  of  dough. 

706  weight  of  pan  and  contained  dough. 
191  grams  weight  of  pan. 

515  grams  of  dough  in  the  pan. 

10  grams  of  dough  left  in  the  kneader. 

515  grams  of  dough  in  pan. 
488  grams  of  bread. 

27  grams  lost  in  baking. 
27  is  5.2  per  cent,  of  515,  or  the  per  cent,  of  the  weight  baked  out. 


386  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION. 

5.2  per  cent,  of  10  is  .5  grams  the  loss  on  the  10  grams  had  it  been 
baked. 

27      grams  given  loss  in  baking. 
.5  loss  on  10  grams  in  the  kneader. 

27.5  loss  on  total  dough. 

525  grams  of  total  dough. 
27.5  grams  loss  in  baking. 


497.5  weight  of  loaf  if  all  the  dough  were  baked. 
454.5  grams  in  a  one-pound  loaf. 

43.0  grams  overweight  when  calculated  to  a  one-pound  loaf. 

A  barrel  of  flour  (196  pounds)  equals  89,082  grams.  When  340 
grams  are  used  per  loaf  there  should  be  262  loaves  made  from  a  barrel 
of  flour. 

43  times  262  equals  11,266  grams  overweight  produced  in  one  barrel 
of  flour. 

454.5  grams  equals  one  pound. 

11266  divided  by  454.5  equals  24  loaves  in  overweight. 

262  loaves  of  340  grams  flour  each  in  one  barrel. 

24  loaves  gain  in  overweight. 
286  loaves  (weighing  one  pound)  made  from  the  tested  flour. 

Volume. — The  volume  of  a  loaf  of  bread  is  even  more  dependent 
upon  the  quality  of  the  gluten  than  upon  its  quantity.  After  the  pan 
of  bread  is  placed  in  the  oven,  the  high  temperature  increases  the  vol- 
ume of  the  gas  within  the  loaf,  and  also  causes  the  formation  of  steam, 
which  together  tends  to  expand  the  dough.  If  the  dough  is  coarse  and 
not  elastic,  the  gases  escape  through  the  pores  into  the  oven,  but  if  the 
gluten  in  the  dough  is  of  good  quality  it  keeps  these  gases  enclosed  which 
cause  the  volume  to  increase. 

If  from  Table  XIX  we  select  the  results  indicating  the  nine  best 
loaves,  as  measured  by  their  volume,  arranging  them  in  order  and  for  the 
sake  of  contrast  select  and  arrange  the  results  from  the  poorest  nine 
loaves  we  have  some  very  interesting  and  suggestive  data.  (See  Table 
XX.) 

The  general  trend  of  results  is  clearly  seen.  Two  unusual  occurrences 
must  be  noticed.  The  first  is  the  relation  of  the  water  holding  capacity 
or  absorption  to  the  gluten  content,  and  to  the  amount  of  gliadin  to  the 
gluten  content.  We  would  expect  to  find  more  difference  in  the  absorp 
tion  number  than  is  shown,  since  the  quality  of  the  gluten  is  very  evi- 
dently different,  as  is  shown  by  the  volume  of  the  loaves.  The  second  is 
the  relation  of  the  gluten  and  loaf  volume  to  the  number  of  loaves  that 
may  be  produced  from  a  barrel  of  flour.  Ordinarily,  we  would  expect 
the  loaf  production  to  increase  with  the  amount  and  quality  of  the 
gluten.  This  would,  probably,  hold  with  flour  of  average  to  good 
quality,  but  with  a  poor  flour,  the  loaf  is  coarser  in  texture  and  has  a 


Bulletin  212] 


CALIFORNIA    WHITE    WHEATS. 


387 


smoother  crust,  and  a  smaller  surface  exposed,  so  that  the  loss  between 
the  weighing  into  the  pan  in  which  it  is  allowed  to  rise  and  the  time  it 
is  baked  may  be  considerably  different.  Then,  too,  the  larger  volume 
of  the  dough  from  good  flour  at  the  first  kneading  permits  of  much  more 
water  being  carried  off  when  the  gases  are  worked  out. 

TABLE  XX. — RESULTS  OF  BAKING  TESTS. 


Laboratory  number. 


H 

0 

S- 

9 

a 

a> 

3 

7.88 

7.65 

7.25 

7.09 

7.32 

7.09 

8.62 

8.21 

9.33 

9.20 

6.96 

6.83 

6.54 

6.42 

7.80 

7.28 

6.74 

6.61 

7.64 

7.38 

4.71 

4.71 

4.94 

4.82 

5.31 

5.18 

6.54 

6.31 

5.02 

4.90 

5.10 

5.10 

6.65 

6.65 

6.00 

6.00 

1    5.74 

5.74 

5.56 

5 

.49 

•a  s 


a 

a 


2§ 


2 

2  2 


25 

17a 

163 

19a 

480 

320 

51a __  — 

41a 

289 

Average 

253 

266 

259 

249  -__ 

317 

268 

254 

228 

269 

Average 


97.0 

4.23 

55.3 

53.7 

97.8 

3.75 

52.9 

51.7 

96.9 

3.83 

54.0 

52.4 

95.2 

4.31 

52.5 

50.0 

98.6 

4.55 

49.5 

48.8 

98.1 

3.15 

46.1 

45.3 

98.2 

3.27 

50.9 

49.8 

93.3 

5.42 

74.5 

69.3 

98.1 

3.58 

54.2 

53.1 

97.0 

4.01 

54.4 

52.7 

10.0 

2.27 

48.1 

48.1 

97.6 

2.47 

51.2 

50.1 

97.6 

2.58 

49.8 

48.5 

96.5 

2.51 

39.8 

38.4 

97.6 

2.67 

54.5 

53.2 

100. 

1.75 

34.3 

34.3 

100. 

2.47 

37.1 

37.1 

100. 

2.47 

41.2 

41.2 

100. 

2.87 

50.0 

50.0 

98.8 

2.45 

45.1 

44.5 

52.9 
52.9 
53.5 
52.4 
50.9 
47.9 
51.8 
53.8 
47.6 

51.5 


50.6 
52.1 
48.2 
53.8 
50.3 
51.8 
54.4 
51.1 
48.5 

51.2 


13.0 

I 
93 

14.0 

93 

10.0 

92 

11.2 

92 

13.0 

91 

6.0 

89 

12.6 

89 

12.1 

88 

11.0 

88 

11.4 

90.5 

11.0 

61 

9.4 

63 

12.0 

69 

10.2 

69 

7.9 

71 

6.7 

76 

11.7 

77 

11.0 

77 

8.5 

81 

9.8 

71.5 

271 
274 

285 
278 
271 
286 
273 
276 
269 

276 


275 

283 
269 
284 
285 
285 
281 
278 
287 

281 


In  Figure  17  (upper  row)  is  shown  the  volume  and  character  of  loaves 
produced  from  certain  flours  of  these  wheats,  No.  5  showing  a  loaf  from 
a  particularly  good  type  of  Little  Club  wheat  flour  from  the  crop  of 
1904,  which  gave  a  volume  of  86  cubic  inches ;  No.  7  made  from  a  Sonora 
flour,  also  of  the  crop  of  1904,  but  having  a  volume  of  only  76  cubic 
inches ;  No.  6  being  from  a  Little  Club  flour,  crop  of  1905,  and  showing 
a  volume  of  only  71  cubic  inches. 

In  the  lower  row  of  the  same  plate  are  three  illustrations  showing 
that  an  increase  of  the  gliadin  ratio  does  not  entirely  govern  the  volume 
of  loaf.  The  flours  selected  to  show  this  had  a  widely  varying  gliadin 
number,  but  the  gluten  content  was  essentially  the  same,  viz. : 


Number. 

r-ei,             ££ 

Volume. 

268 _ 

5.10 
5.22 
5.02 

34.66 
48.52 
54.65 

76 

272 

82 

317 

71 

388 


UNIVERSITY    OF   CALIFORNIA — EXPERIMENT   STATION. 


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Fig.   17. — Relation  of  volume  to  gliadin  ratio. 

First,  the  higher  the  gluten  the  larger  the  volume  of  loaf,  other  things 
being  equal. 

Second,  it  seems  to  further  show  that  an  increase  in  the  gliadin  ratio 
is  favorable  to  the  production  of  a  better  loaf.  This,  together  with  the 
fact  that  the  gliadin  number  and  protein  content  of  these  wheats  are 
both  relatively  low  would  seem  to  indicate  that  the  generally  poor 
quality  of  these  flours  is  due  to  a  lack  of  development  of  glutenin  rather 
than  of  gliadin. 

Third,  the  absorptive  power  in  these  wheats  would  seem  to  have  no 
close  relation  to  the  loaf  volume,  as  the  loaf  volume  varies  widely  in 
these  two  groups  while  the  absorptitve  power  remains  essentially  the 
same. 


Bulletin  212]  CALIFORNIA  WHITE  WHEATS.  389 

Table  No.  XX  shows  that  the  volume  of  the  loaf  is  not  parallel  with 
the  gliadin  number.  There  is  shown,  however,  a  somewhat  general 
relation  between  the  volume  of  the  loaf  and  the  percentage  loss  in  the 
process  of  baking.  This  relation  is  quite  constant.  The  larger  the 
volume  of  a  loaf,  the  larger  the  amount  of  loss  in  baking  and  the  lighter 
and  whiter  the  bread  becomes.  The  whiter  and  lighter  loaves  have 
been  shown  to  be  the  more  nutritious  than  heavier  and  darker  ones. 
These  two  characters  are  very  important  then,  and  since  the  amount  of 
loss  in  baking  is  an  indication  of  each,  when  the  comparison  is  made 
between  breads  from  similar  flours,  it  is  a  valuable  determination. 

The  number  of  loaves  of  bread  of  the  same  size  that  a  flour  will  yield 
is  a  matter  of  considerable  importance  and  one  that  is  very  carefully 
considered  by  the  bakers.  The  ordinary  housewives  would  do  well  to 
pay  some  attention  to  this  feature. 

In  the  flours  studied  this  variation  ranged  from  260  up  to  289  one- 
pound  loaves  per  barrel  and  in  the  case  of  standard  297  loaves  per  bar- 
rel, with  a  volume  as  high  as  108  cubic  inches. 

Texture. — The  texture  of  the  loaves  is  seen  on  cutting  them  open 
after  they  have  cooled.  In  deciding  upon  this,  account  is  taken  of  the 
color  of  the  crust  and  crumb,  the  crust  should  present  fine  even  pores 
with  no  roughness  or  cracks.  The  crumbs  should  be  uniform  through- 
out as  regards  evenness  and  the  size  of  the  pores.  The  body  should  be 
moist,  soft,  and  friable.  When  touched  with  the  finger,  it  should  leave 
no  dent.  The  membraneous  partitions  between  the  pores  should  be 
even  and  thin.  In  no  case  should  there  be  any  unexpanded  masses 
either  glutinous  or  floury. 

In  general,  the  texture  of  loaves  from  these  flours  was  poor,  not  that 
it  was  due  to  insufficient  working  of  the  dough  or  insufficient  time  ir 
rising,  but  rather  to  the  quality  and  quantity  of  the  gluten.  In  many 
instances  the  loaf  broke,  and  in  others  the  crust  remained  intact  but 
the  crumb  had  not  developed  evenly.  We  may  say  that  those  flours 
with  less  than  5.25  per  cent,  proteids  can  not  be  baked  into  well-formed 
loaves  under  our  conditions.  Were  it  attempted  to  have  them  raise  to 
the  same  height  in  the  pan  as  is  common  with  eastern  flours,  there  would 
be  few  that  could  stand  the  test. 

SEASONAL  EFFECT  ON  CHARACTER  OF  LOAF. 

The  following  illustration  (Figure  18)  fairly  represents  the  general 
difference  in  the  flours  as  affected  by  the  season  as  shown  in  the  bak- 
ing. Nos.  1  and  3  were  from  the  crop  of  1904  and  Nos.  2  and  4  from 
the  crop  of  1905,  all  the  flours  of  the  latter  season  giving  poorer  results 
than  those  of  1904. 


390  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION. 

The  figures  for  the  loaves  are  subjoined : 


No.  1  (62a).       No.  3  (19a) 


1905 


No.  2  (231).      No.  4  (10a) 


Total  protein  _ 

Gliadin  

Gliadin  number 

Volume  of  loaf. 


7.97 
4.15 
52.0 

90  cu.  in. 


8.62 
4.31 
5.00 


8.62 
2.33 


92  cu.  in.     78  cu.  in. 


7.08 
4.43 
62.6 

81  cu.  in. 


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Fig.   18. — Showing  difference  in  loaf  as  affected  by  season. 

Acidity. — The  acidity  of  Californian  white  wheats  is  rather  low. 
This  may  be  expected  when  we  remember  that  the  latter  part  of  the 
growing  season  is  passed  in  a  warm  and  dry  condition,  there  being  no 
rain  to  keep  the  grain  green.  Then,  too,  the  grain  is  well  matured  and 
perfectly  dry  by  reason  of  being  left  standing  so  long  before  the  harvest 
can  be  completed.  So  there  is  very  little  immature  or  "musty"  wheat. 
The  flour  contains  less  fat  and  less  branny  portion  with  foreign  particles, 
thus  the  chances  for  fermentation  are  fewer,  and  the  acidity  lower. 
The  determination  was  made  on  five  grams  of  flour  using  one  tenth 
sodium  hydrate  with  phenolphthalein  and  the  result  calculated  to  lactic 
acid.  The  range  was  from  .049  to  .165  per  cent  and  averaging  .095 
for  all.  The  following  tabulation  gives  the  maximum  average,  and 
minimum  for  the  flours  from  the  different  wheats. 


Kinds  of  Flours. 

Maximum. 

Average. 

Minimum. 

Bluestem _  _           _ 

.1086 
.1650 
.1485 
.0976 

.0879 
.0999 
.0890 
.0945 

0950 
.112 

.0660 

Australian         _.               _    -_ 

.088 

Club    

.0495 

Sonora      _  _           _               _  _        _  _ 

.088 

Average  for   all__ 

Standard      _ 

Bulletin  212] 


CALIFORNIA   WHITE    WHEATS. 


391 


For  the  purpose  of  comparing  the  proximate  analysis  of  the  type  of 
wheats  with  the  corresponding  flours,  those  samples  which  were  used 
for  milling  and  baking  tests  were  subjected  to  complete  analysis  and  the 
results  are  contrasted  in  the  following  table : 


Australian. 

Bluestem. 

Little  Club. 

Sonora. 

3 

o 

e 

m 
9 

3 

o 

9 

2 

o 

c 

3 

2 

o 

c 

Moisture 

10.34 
1.73 
8.39 
2.39 

1.42 
2.67 

13.24 

.49 

6.73 

.19 

1.00 
3.34 

11.88 
1.69 

8.32 

2.78 

1.60 

2.82 

13.31 

.47 

6.61 

.09 

.96 
3.31 

12.03 
1.87 
8.31 
2.69 

1.57 
2.94 

13.13 

.45 

6.59 

.12 

.95 
3.39 

12.29 
1.69 
7.52 
2.12 

1.41 

2.48 

13.77 

Ash    

.46 

Total  protein 

6.39 

Crude  fiber 

.07 

Nitrogen-free  extract — 
Fat    

1.10 

Gliadin 

2.78 

Ash. — The  ash  of  these  wheat  flours  is  very  low,  averaging  .55  per 
cent,  and  ranging  from  a  minimum  of  .32  per  cent,  in  Little  Club  253 
to  a  maximum  of  .72  per  cent,  in  Bluestem  260. 

Fat  and  Fiber. — Both  of  these  groups  are  so  low  as  to  not  appre- 
ciably affect  the  flour.  The  fat  averages  but  .98  per  cent,  as  against 
2.24  per  cent  in  Minnesota  flours  (Minn.  Bui.  74,  p.  157),  and  1.85  for 
Canadian  wheats  (Bui.  50,  Central  Exp.  Farm,  Ottawa,  Canada). 
This  low  fat  content  may  explain  the  high  keeping  quality  of  these 
flours.  Certain  it  is  that  the  Minnesota  "Standard"  brought  from 
Minnesota  at  the  beginning  of  these  experiments  has  deteriorated  very 
noticeably  within  six  months,  while  the  native  flours  do  not  show  any 
appreciable  change. 

BRAN,  SHORTS,  AND  LOW  GRADE  FLOURS. 

Bran,  shorts,  and  the  low  grade  flours  are  the  by-products  produced 
in  the  manufacture  of  flour.  The  floury,  white  content  of  the  grain  is 
the  valuable  portion.  The  by-products  consist  of  the  fibrous  coverings 
of  the  kernels,  the  germ  and  unavoidable  loss  of  the  starch  wThich  is 
removed  along  with  the  undesirable  parts.  The  yield  of  each  depends 
upon  the  'kind  and  condition  of  the  grain,  upon  the  method  of  milling 
and  upon  the  skill  of  the  miller.  By  improperly  supplying  the  grain 
to  the  rolls  and  manipulating  of  the  streams  after  bolting,  a  large 
amount  of  flour  may  find  its  way  into  the  feed  stuffs  or  some  of  the  feed 
stuffs  may  be  turned  into  the  flour  streams  and  thus  affect  not  only  the 
color  and  quality  of  the  flour,  but  also  impair  its  breadmaking  quality 
and  its  nutritive  value.  The  bran  and  shorts  are  not  very  different 
either  in  the  nature  of  the  material  or  in  the  composition.  In  years 
past,  when  the  flour  was  not  so  completely  removed,  the  shorts  had  con- 
siderable more  value  as  a  foodstuff  than  bran,  as  it  contained  considera- 
bly more  of  the  middlings  which  the  then  used  process  could  not  reduce, 
the  bran  being  left  in  a  coarser  condition.    But  the  improved  methods 


392 


UNIVERSITY   OF    CALIFORNIA EXPERIMENT    STATION. 


have  swept  away  this  difference.  The  shorts  is  now  a  little  more  than 
finely  ground  bran  with  perhaps  some  ground  screening  and  the  sweep- 
ings added  to  it. 

The  low  grade  flour  is  composed  largely  of  the  germ  parts,  the  very 
fine  particles  of  bran  and  fibrous  parts  under  the  bran  which  are  una- 
voidably obtained  in  the  middlings.  To  this  must  be  added  the  very 
fine  specks  of  dust  and  hairs  of  the  surface  of  the  grain  which  were  not 
previously  removed,  and  the  small  amount  of  flour  that  is  lost  from  the 
chop  produced  in  removing  the  above  debris.  The  amount  thus  turned 
into  low  grade  flour  may  vary  considerably,  depending  upon  the  condi- 
tion of  the  grain,  the  process  and  the  kind  of  flour  being  produced 
When  milling  for  a  straight  grade  flour  from  soft  wheat,  very  little  low 
grade  flour  need  result  to  make  it  comparable  to  eastern  straight  flours. 

In  commercial  milling,  the  bran  and  shorts  may  amount  to  22  or  25 
per  cent  of  the  grain  used  and  the  low  grade  flour  from  2  to  10  per  cent, 
or  even  more.  On  a  small  experimental  mill  it  would  be  impracticable 
to  get  large  yields  of  flour,  and  it  is  not  necessary  in  order  to  obtain 
comparable  results. 

The  attached  Table  No.  XXI  gives  the  results  of  the  determinations 
made  on  the  products.  While  they  are  comparable  among  themselves 
they  are  lower  in  every  respect  with  the  exception  of  the  proteids, 
which  are  higher  than  they  would  have  been  had  they  been  obtained  in 
commercial  milling. 

TABLE  XXI.— SHOWING  AVERAGE  ANALYSES  OF  BRAN,  SHORTS,  AND  LOW- 
GRADE  FLOUR  FROM  WHITE  WHEATS. 

BRAN. 

Bluestem. 


Moisture. 

Ash. 

Total 
protein. 

Fat.* 

Fiber. 

Maximum   

13.80 
12.84 
11.36 

5.71 
5.29 
4.73 

12.44 
10.39 

8.62 

2.73 
2.27 
2.06 

13.11 

Average 

11.55 

Minimum 

9.76 

Club. 

Maximum   __ 

13.57 
12.19 

8.86 

5.90 
5.59 
4.97 

14.04 

10.73 

9.01 

2.87 
2.67 
2.52 

12.03 

Average 

10.61 

Minimum 

9.44 

Australian. 

Maximum    .__ 

13.53 
12.80 
11.86 

6.01 
5.29 
4.46 

15.22 

10.72 

7.80 

2.53 
2.42 
2.29 

10.96 

Average __ _  _ 

10.17 

Minimum  __  _  _      _  _ 

9.47 

Sonora. 

Maximum     _  

12.85 
12.60 
12.33 

5.20 

4.82 
4.29 

10.11 
9.04 
7.97 

Average __     

2.35 

8.41 

Minimum 

•Determination  made  on  <  nmposite  sample. 


Bulletin  212] 


CALIFORNIA   WHITE    WHEATS. 


393 


SHORTS. 

Bluestem. 


Maximum 
Average  . 
Minimum 


14.12 
13.22 
12.30 


4.71 
4.10 
3.10 


14.91 
11.79 
10.03 


4.26 
3.99 
3.48 


7.57 
6.98 
6.00 


Club. 


Maximum 
Average  . 
Minimum 


13.99 
12.24 
11.29 


4.84 
4.25 
2.89 


14.28 

12.09 

9.83 


4.51 
4.27 
4.06 


8.17 
749 
6.44 


Australian. 

Maximum     

14.02 
12.43 
11.51 

4.89 
4.31 
3.68 

16.74 
11.93 

8.70 

4.35 
4.08 
3.71 

7.77 

Average 

7.05 

Minimum 

6.49 

Sonora. 


Maximum 
Average  . 
Minimum 


12.85 
12.60 
12.33 


5.20 
4.82 
4.29 


10.11 
9.04 
7.97 


3.81 


5.79 


LOW-GRADE  FLOUR. 

Bluestem. 


Moisture. 

Ash. 

Total 
protein. 

Fat.* 

Tiber. 

Maximum    _ 

14.14 
13.30 
11.68 

2.47 
1.82 
1.25 

13.32 
9.63 
7.80 

2.92 
2.67 
2.27 

1.86 

Average  

1.39 

Minimum  

1.07 

Club. 

Maximum 

13.91 
13.01 
12.30 

2.85 
1.35 
1.32 

11.80 
9.18 
7.08 

3.39 
2.82 
2.36 

2.03 

Average 

1.72 

Minimum  

1.37 

Australian. 


Maximum                  

13.71 

12.88 
11.58 

2.73 
1.96 
1.42 

13.56 

10.05 

7.97 

3.15 
2.70 
1.82 

2.64 

Average                 

1.98 

Minimum  

1.50 

Sonora 

Maximum                             

13.70 
13.61 
13.52 

2.14 
1.86 
1.63 

9.49 
8.61 

7.72 

Average                           

3.03 

1.67 

Minimum   

*  Determination  made  on  composite  sample. 


6— b212 


394  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION. 

Under  shorts,  there  is  a  maximum  of  total  protein  in  the  Australian 
wheats  given  of  16.74  per  cent.  This  is  of  interest  in  that  it  suggests  a 
wheat  with  a  high  protein  content.  Tracing  it  back  to  the  wheat  we  find 
it  has  15.22  per  cent  in  the  bran,  13.56  per  cent  in  the  low  grade  flour, 
11.72  per  cent  in  the  whole  wheat  and  only  7.80  per  cent  in  the  flour. 
This,  then,  is  a  case  of  high  protein  wheat  yielding  a  flour  with  a  rela- 
tively low  amount.  This  suggests  the  need  of  looking  further  than  to  the 
nitrogen  content  of  a  wheat  as  indicative  of  its  value  for  the  improving 
the  bread-making  quality  of  the  same.  This  same  wheat  has  also  a  fair 
amount  of  gluten,  having  90  per  cent,  of  the  total  proteids  in  the  form 
of  gluten. 

SOME  CONCLUSIONS. 

(1)  The  California  white  wheats  have  a  low  nitrogen  and  protein 
content. 

(2)  The  larger  normal  kernels  usually  carry  a  higher  per  cent,  of 
nitrogen  than  smaller  normal  kernels  of  the  same  type. 

(3)  The  California  white  wheats  are  relatively  high  in  fiber  and  low 
in  ash  and  ether  extract  as  compared  with  the  hard  winter  wheats. 

(4)  The  wheat  crop  of  1905  contained  a  uniformly  lower  nitrogen 
content  than  did  the  crop  of  1904. 

(5)  The  overlap  of  gluten  nitrogen  in  the  salt  soluble  extract  is  rep- 
resented in  the  case  of  white  wheat  meals  by  the  factor  .15  per  cent. ; 
for  flour  .22  per  cent. 

(6)  The  polariscopic  method  for  the  determination  of  gliadin  has 
proven  very  reliable. 

(7)  The  mechanical  separation  of  gluten  in  the  case  of  this  class  of 
wheats  is  very  unsatisfactory. 

(8)  The  California  white  wheats  contain  a  larger  proportion  of  their 
total  protein  in  the  form  of  gluten  than  do  most  other  wheats. 

(9)  The  gliadin-number  of  these  wheats  is  much  lower  than  for  those 
of  the  middle  west. 

(10)  These  wheats  ordinarily  produce  a  very  white  flour  which 
bakes  darker  than  the  tinted  flours  from  winter  wheats. 

(11)  The  water  absorption  of  these  wheats  is  relatively  low.  The 
white  wheat  flours  absorb  about  52  per  cent.,  while  the  hard  spring 
wheat  flours  absorb  about  58  per  cent. 

(12)  Loaves  showing  the  greater  loss  in  baking,  other  things  being 
equal,  are  the  lighter  and  whiter. 

(13)  Glutens  from  white  wheat  flours  are  not  tenacious  according  as 
they  contain  more  gliadin. 

(14)  The  gluten  of  these  wheats  hydrolyze  more  than  for  other  types 
of  wheat. 

(15)  The  glutens  of  these  wheats  are  usually  inferior  in  quality  and 
dull  in  color. 


STATION    PUBLICATIONS    AVAILABLE     FOR     DISTRIBUTION. 


REPORTS. 

1896.  Report  of  the  Viticultural  Work  during  the  seasons  1887-93,  with  data  regard- 

ing the. Vintages  of  1894-95. 

1897.  Resistant  Vines,  their  Selection,  Adaptation,  and  Grafting.     Appendix  to  Viti- 

cultural Report  for  1896. 

1902.  Report  of  the  Agricultural  Experiment  Station  for  1898-1901. 

1903.  Report  of  the  Agricultural  Experiment  Station  for  1901-03. 

1904.  Twenty-second  Report  of  the  Agricultural  Experiment  Station  for  1903-04. 


BULLETINS. 

Reprint.  Endurance  of  Drought  in  Soils  of    No.  186. 
the   Arid  Regions.  187. 

No.  128.  Nature,  Value,  and  Utilization  of 

Alkali  Lands,  and  Tolerance  of  188. 

Alkali.      (Revised  and  Reprint, 

1905.)  189. 

133.  Tolerance    of    Alkali    by    Various 

Cultures.  190. 

147.   Culture  Work  of  the  Sub-stations.  191. 

149.  California   Sugar  Industry.  192. 

151.  Arsenical   Insecticides. 

153.   Spraying    with    Distillates.  193. 

159.  Contribution  to  the  Study  of  Fer- 
mentation. 

162.  Commercial  Fertilizers.      (Dec.   1,  194. 

1904.) 

165.  Asparagus    and    Asparagus    Rust  195. 

in  California.  197. 

167.  Manufacture    of    Dry    Wines    in 

Hot  Countries. 

168.  Observations  on   Some  Vine   Dis- 

eases  in   Sonoma   County.  198. 

169.  Tolerance   of  the   Sugar  Beet  for  199. 

Alkali.  200. 

170.  Studies  in  Grasshopper  Control. 

171.  Commercial  Fertilizers.      (June  30,  201. 

1905.) 

172.  Further  Experience  in  Asparagus  202. 

Rust  Control. 
174.  A  New  Wine-cooling  Machine.  203. 

176.  Sugar   Beets  in   the   San   Joaquin 

Valley.  204. 

177.  A    New    Method    of    Making    Dry 

Red   Wine.  205. 

178.  Mosquito  Control. 

179.  Commercial     Fertilizers.        (June,  206. 

1906.) 

180.  Resistant  Vineyards.  207. 

181.  The   Selection  of   Seed-Wheat.  208. 

182.  Analysis  of  Paris  Green  and  Lead  209. 

Arsenic.      Proposed    Insecticide  210, 

Law. 
.183.  The  California  Tussock-moth.  211. 

184.  Report    of   the    Plant    Pathologist 

to  July  1,   1906. 

185.  Report  of  Progress  in  Cereal  In- 

vestigations. 


The  Oidium  of  the  Vine. 
Commercial  Fertilizers.    (January, 
1907.) 

Lining  of  Ditches  and  Reservoirs 
to  Prevent  Seepage  and  Losses. 

Commercial  Fertilizers.  (June, 
1907.) 

The  Brown  Rot  of  the  Lemon. 

California  Peach   Blight. 

Insects  Injurious  to  the  Vine  in 
California. 

The  Best  Wine  Grapes  for  Cali- 
fornia ;  Pruning  Young  Vines ; 
Pruning  the  Sultanina. 

Commercial  Fertilizers.  (Dec, 
1907.) 

The  California  Grape  Root-worm. 

Grape  Culture  in  California;  Im- 
proved Methods  of  Winemak- 
ing;  Yeast  from  California 
Grapes. 

The   Grape  Leaf-Hopper. 

Bovine  Tuberculosis. 

Gum  Diseases  of  Citrus  Trees  in 
California. 

Commercial  Fertilizers.  (June, 
1908.) 

Commercial  Fertilizers.  (Decem- 
ber,  1908.) 

Report  of  the  Plant  Pathologist 
to  July   1,    1909. 

The  Dairy  Cow's  Record  and  the 
Stable. 

Commercial  Fertilizers.  (Decem- 
ber,   1909.) 

Commercial  Fertilizers.  (June, 
1910.) 

The  Control  of  the  Argentine  Ant. 

The  Late  Blight  of  Celery. 

The  Cream  Supply. 

Imperial  Valley  Settlers'  Crop 
Manual. 

How  to  Increase  the  Yield  of 
Wheat  in  California. 


CIRCULARS. 


No. 


1. 

5. 
.7. 

9. 
10. 

11. 
12. 
15. 

17. 

19. 

29. 


39. 


4  6. 


Texas  Fever. 

Contagious  Abortion  in  Cows. 

Remedies  for  Insects. 

Asparagus  Rust. 

Reading  Course  in  Economic  Ento- 
mology.     (  Revision. ) 

Fumigation   Practice. 

Silk  Culture. 

Recent  Problems  in  Agriculture. 
What  a  University  Farm  is  For. 

Why  Agriculture  Should  be  Taught 
in  the  Public  Schools. 

Disinfection  of  Stables. 

Preliminary  Announcement  Con- 
cerning Instruction  in  Practical 
Agriculture  upon  the  University 
Farm,  Davisville,  Cal. 

White  Fly  in  California. 

White  Fly  Eradication. 

Packing  Prunes  in  Cans.  Cane 
Sugar  vs.  Beet  Sugar. 

Analyses  of  Fertilizers  for  Con- 
sumers. 

Instruction  in  Practical  Agriculture 
at  the  University  Farm. 

Suggestions  for  Garden  Work  in 
California    Schools. 


No.  47. 
48. 
49. 
50. 
51. 
52. 


54. 


55. 


57. 


59. 

60. 
61. 

62. 


Agriculture  in  the  High  Schools. 
Butter  Scoring  Contest,  1909. 
Insecticides. 
Fumigation  Scheduling. 
University  Farm  School. 
Information  for  Students  Concern- 
ing the  College  of  Agriculture. 
Announcement   of   Farmers'    Short 

Courses  for  1910. 
Some      Creamery     Problems     and 

Tests. 
Farmers'  Institutes  and  University 

Extension  in  Agriculture. 
Announcement    of    Farmers'    Short 

Courses  in  Animal  Industry  and 

Veterinary  Science. 
Experiments  with  Plants  and  Soils 

in      Laboratory,      Garden,      and 

Field. 
Tree      Growing      in      the      Public 

Schools. 
Butter  Scoring  Contest. 
University  Farm  School. 
The   School  Garden   in   the   Course 
of  Study. 


